UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE

SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant  ☒

Filed by a Party other than the Registrant  ☐

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SERVICESOURCE INTERNATIONAL, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

Dear Fellow Stockholders:

You are cordially invited to join us for our 2018 annual meeting of stockholders, which will be held on May 16, 2018, at 9:00 a.m. local time at our Corporate Headquarters located at 717 17^th Street, 5^th Floor, Denver, Colorado 80202. Holders of record of our common stock as of March 19, 2018 are entitled to notice of, and to vote at, the 2018 annual meeting.

The Notice of Annual Meeting of Stockholders and the proxy statement that follow describe the business to be conducted at the meeting. We may also report on matters of current interest to our stockholders at that meeting.

We are pleased to be furnishing these materials to our stockholders via the internet. We believe this approach provides you with the information that you need while expediting your receipt of these materials, lowering our costs of delivery, and reducing the environmental impact of our annual meeting. If you would like us to send you printed copies of our proxy statement and accompanying materials, we will be happy to do so at no charge upon your request. For more information, please refer to the Notice of Internet Availability of Proxy Materials that we previously mailed to you on or about April 4, 2018.

You are welcome to attend the meeting. However, even if you plan to attend, please vote your shares promptly and prior to the meeting to ensure they are represented at the meeting. You may submit your proxy by internet or telephone, as described in the following materials, or, if you request printed copies of these materials, by completing and signing the proxy or voting instruction card enclosed therein and returning it in the envelope provided. If you decide to attend the meeting and wish to change your proxy, you may do so automatically by voting in person at the meeting.

If your shares are held in the name of a broker, bank, trust or other nominee, you may be asked for proof of ownership of these shares to be admitted to the meeting.

We thank you for your support.

Sincerely,

Christopher M. Carrington

Chief Executive Officer

NOTICE OF 2018 ANNUAL MEETING OF STOCKHOLDERS

ITEMS OF BUSINESS:

We also will transact any other business that may properly come before the meeting or at any adjournments thereof. We are not aware of any other business to come before the meeting at this time.

Only stockholders of record at the close of business on March 19, 2018, or their valid proxies, are entitled to attend and vote at the meeting and any and all adjournments or postponements of the meeting.

Your vote is important. Whether or not you plan to attend the annual meeting, we encourage you read the proxy statement and to vote as promptly as possible. For specific instructions on how to vote your shares, please refer to the instructions in the section entitled “How to Vote” beginning on page 1 of the proxy statement.

By order of the board of directors,

Christopher M. Carrington

Chief Executive Officer

Denver, Colorado

April 4, 2018

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON MAY 16, 2018: THIS PROXY STATEMENT AND SERVICESOURCE’S 2017 ANNUAL REPORT ON FORM 10-K ARE AVAILABLE AT IR.SERVICESOURCE.COM. ADDITIONALLY, AND IN ACCORDANCE WITH RULES OF THE U.S. SECURITIES AND EXCHANGE COMMISSION (“SEC”), YOU MAY ACCESS THESE MATERIALS AT WWW.PROXYDOCS.COM/SREV.

PROXY STATEMENT

FOR 2018 ANNUAL MEETING OF STOCKHOLDERS

TABLE OF CONTENTS

Proxy Statement

We are providing these proxy materials in connection with the solicitation by our board of directors of proxies to be voted at our 2018 annual meeting of stockholders, which will take place on Wednesday, May 16, 2018 at 9:00 a.m., Mountain Time, at our Corporate Headquarters located at 717 17^th Street, 5^th Floor, Denver, Colorado 80202. As a stockholder, you are invited to attend the annual meeting and are requested to vote on the items of business described in this proxy statement.

This proxy statement and the accompanying proxy card, notice of annual meeting and voting instructions are being distributed and made available on or about April 4, 2018 to all stockholders of record entitled to vote at the annual meeting.

How To Vote

in advance of the annual meeting

Even if you plan to attend the annual meeting in person, please vote as promptly as possible using one of the following voting methods. Make sure you have your proxy/voting instruction card in hand and follow the instructions. You can vote in advance in one of the following three ways – and in each case, votes must be cast prior to 5 p.m., Mountain Time on Tuesday, May 15, 2018:

Proxy Summary

This summary highlights information generally contained elsewhere in this proxy statement. This summary does not contain all of the information you should consider, and you should read the entire proxy statement carefully before voting.

Date, Time and Place of Meeting

Voting Matters and Board Recommendations

The following proposals will be considered at the Annual Meeting:

Proposal 1: Election of Directors

Each Class I director nominee currently is up for election for a three-year term. Each director nominee is a current director and during 2017 attended at least 75% of the aggregate of all meetings of the Board and of all Board committees on which he or she sits.

Our board of directors recommends that stockholders vote FOR each director nominee.

Proposal 2: Approval of an Amendment to Certificate of Incorporation to Provide for Annual Election of All Directors

Article VI of our certificate of incorporation currently provides that the board of directors shall be classified into three classes with each class holding office for a three-year term. If our stockholders approve the declassification amendment to our certificate of incorporation, our directors would be elected to annual terms beginning at our 2019 annual meeting of stockholders. The text of the amendment, marked to show the proposed deletions and insertions, is attached as Appendix A to this proxy statement. Our board of directors recommends that stockholders vote FOR the declassification amendment.

Proposal 3: Advisory Vote to Approve Compensation of our Named Executive Officers

Stockholders will be given the opportunity to vote on an advisory resolution to approve the compensation of our named executive officers (commonly referred to as the “say-on-pay” vote).

Our executive compensation program is designed to drive and reward superior corporate performance, both annually and over the long-term. The board of directors believes the Company’s compensation policies and practices are effective in achieving the Company’s goals of paying for performance and aligning the named executive officers’ long-term interests with those of our stockholders. Compensation elements for our named executive officers include:

Our board of directors recommends that stockholders vote, on an advisory basis, FOR our say-on-pay proposal.

Proposal 4: Advisory Vote on the Frequency of the Advisory Vote on Executive Compensation

Stockholders will be given the opportunity to vote on an advisory resolution on the frequency of the advisory vote to approve the compensation of our named executive officers (commonly referred to as the “say-on-frequency” vote). Currently, we hold the say-on-pay vote every year. At our 2012 annual meeting of stockholders, our board of directors recommended, and our stockholders approved, on an advisory basis, that we hold our say-on-pay vote every year. The voting options are to hold a say-on-pay vote every 1 year, every 2 years or every 3 years. Our board of directors recommends that stockholders vote, on an advisory basis, on the frequency of our say-on-pay vote to be held every 1 year (ONE YEAR).

Proposal 5: Ratification of Independent Registered Public Accounting Firm

Ratify the selection of Ernst & Young LLP as the Company’s independent public accounting firm for the 2018 fiscal year. Our board of directors recommends that stockholders vote FOR ratification of Ernst & Young LLP as the Company’s independent auditor for the 2018 fiscal year.

Other Matters

The management and board of directors of the Company know of no other matters to be brought before the meeting. If other matters are properly presented to the stockholders for action at the meeting or any adjournments or postponements thereof, it is the intention of the proxy holders named in this proxy to vote in their discretion on all matters on which the shares of common stock represented by such proxy are entitled to vote. The entire cost of this solicitation of proxies will be borne by the Company, including expenses incurred in connection with preparing, assembling and mailing the Notice. The Company may reimburse brokers or persons holding stock in their names or in the names of their nominees for their expenses in sending the proxy materials to beneficial owners who request paper copies. Certain officers, directors and regular employees of the Company, who will receive no extra compensation for their services, may solicit proxies by mail, telephone, facsimile, email or personally.

Corporate Governance Practices at a Glance

Board of Directors Overview

BOARD OF DIRECTORS AND CORPORATE GOVERNANCE

Role and Composition of the Board

Our board of directors is currently composed of eight members. Our bylaws permit our board of directors to establish by resolution the authorized number of directors, and eight directors are currently authorized. Upon the recommendation of our nominating and corporate governance committee, we are nominating Robert G. Ashe, Bruce W. Dunlevie and Barry D. Reynolds for re-election to our board of directors. If re-elected, Messrs. Ashe, Dunlevie, and Reynolds will each hold office for a three-year term until our annual meeting of stockholders to be held in 2021, as further described below.

Our certificate of incorporation and bylaws currently provide for a classified board of directors consisting of three classes of directors, each serving staggered three-year terms, as follows:

Upon expiration of the term of a class of directors, directors (who are up for re-election) for that class will be up for election for three-year terms at the annual meeting of stockholders in the year in which that term expires. Each director’s term continues until the election and qualification of his or her successor, or his or her earlier death, resignation or removal. Any increase or decrease in the number of directors will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the directors. This current classification of our board of directors may have the effect of delaying or preventing changes in control of our Company. If, however, our stockholders approve Proposal 2 in this proxy statement, each member of our board of directors whose term does not immediately expire at our 2019 annual meeting will resign and be immediately re-appointed to a term that expires at our 2019 annual meeting, as further described under “Proposal Number 2 – Vote to Amend our Certificate of Incorporation to Declassify our Board of Directors.” In that case, all eight directors would therefore stand for election for one-year terms beginning at our 2019 annual meeting.

Our board of directors is responsible for, among other things, overseeing the conduct of our business, reviewing and, where appropriate, approving our long-term strategic, financial and organizational goals and plans, and reviewing the performance of our Chief Executive Officer and other members of senior management.

Board Leadership Structure

Lead Independent Director

Bruce W. Dunlevie is our lead independent director. As our lead independent director, Mr. Dunlevie is responsible for helping to set the agendas for board meetings, coordinating the activities of the independent directors and presiding over board meetings if the chairperson is absent (or, as is currently the case, if the position of chairperson is not filled). In addition, the lead independent director presides over executive sessions without the presence of the non-independent directors or members of the Company’s management from time to time as deemed necessary or appropriate. The role given to the lead independent director helps ensure a strong, independent and active board of directors.

Chairperson of the Board

Our board of directors has approved the current separation of the roles of chairperson of the board and Chief Executive Officer, because given the attention, time, effort, and energy that the Chief Executive Officer is required to dedicate to his or her position, and the high level of commitment required to serve as our board chairperson, a separate leadership structure is more appropriate for the Company. Accordingly, although the chairperson role would work closely with the Chief Executive Officer and other members of our management, the board chairperson would not be part of management and would not have an operating or external role or responsibility. The position of chairperson of our board of directors is currently vacant.

Director Independence and Tenure

Under the rules of the NASDAQ Global Select Market (“NASDAQ”), where our common stock trades, independent directors must constitute a majority of a listed company’s board of directors. In addition, the rules of NASDAQ require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent. Audit committee members must also satisfy the independence criteria set forth in Rule 10A-3 under the Exchange Act. Under the rules of NASDAQ, a director will only qualify as an “independent director” if, in the opinion of that company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries, or be an affiliated person of the listed company or any of its subsidiaries.

Based upon information requested from and provided by each director concerning his background, employment and affiliations, including family relationships, our board of directors has determined that none of the following non-employee directors has a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and that each of these directors is “independent” as that term is defined under the rules of NASDAQ: Robert G. Ashe, Bruce W. Dunlevie, Thomas F. Mendoza, Gary B. Moore, Madhu Ranganathan, Barry D. Reynolds and Richard G. Walker. Our board of directors also determined each of the members of our audit committee, our compensation committee, and our nominating and corporate governance committee satisfy the independence standards for those committees established by the applicable rules and regulations of the SEC and NASDAQ.

In making these determinations, our board of directors considered the relationships that each non-employee director has with our Company and all other facts and circumstances our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director.

Board’s Role in Risk Oversight

Our board of directors, as a whole and through its committees, has responsibility for the oversight of risk management. Our senior management is responsible for assessing and managing our risks on a day-to-day basis.

Each of our committees reports to the full board of directors with respect to these matters, among others.

At periodic meetings of the board of directors and its committees and in other meetings and discussions, management reports to and seeks guidance from the board of directors and its committees with respect to the most significant risks that could affect our business, such as legal, compliance, financial, tax and audit related risks. In addition, among other matters, management provides our audit committee periodic reports on our compliance programs and efforts.

Board Committees

Our board of directors has three standing committees: an audit committee, a compensation committee and a nominating and corporate governance committee. The composition and primary responsibilities of each committee are described below. Members serve on these committees until their resignation or until otherwise determined by our board of directors.

Committee Composition

* – Independent Director M – Member C – Chair

Our audit committee is responsible for, among other things:

Our compensation committee is responsible for, among other things:

See “Compensation of Non-Employee Directors” and “Executive Compensation” for a description of our processes and procedures for the consideration and determination of director and executive compensation.

Our nominating and corporate governance committee is responsible for, among other things:

2017 Board Meetings

During 2017, our board of directors met four times. Each of our directors attended or participated in at least 75% of the aggregate of (i) the total number of meetings of our board of directors held during the period for which he or she has been a director and (ii) the total number of meetings held by all committees of our board of directors on which he or she served during the time he or she was a member of such committee in 2017.

Executive Sessions of Independent Directors

Independent members of our board of directors convene executive sessions without the presence of our non-independent directors or members of the Company’s management from time to time as deemed necessary or appropriate. Mr. Carrington does not participate in such sessions.

Compensation Committee Interlocks and Insider Participation

Messrs. Madden, Mendoza, Moore, and Reynolds served as members of our compensation committee during 2017. None of the members of our compensation committee is, or was during 2017, an officer or employee of ours. None of our executive officers currently serves, or in the past year has served, as a member of the board of directors or compensation committee of any entity that has one or more executive officers serving on our board of directors or compensation committee.

Code of Business Conduct and Ethics

We are committed to the highest standards of integrity and ethics in the way we conduct our business. Accordingly, we adopted a Code of Business Conduct and Ethics that applies to our board of directors, officers and employees, including our Chief Executive Officer, Chief Financial Officer and other principal executive and senior financial officers. Our Code of Business Conduct and Ethics establishes our policies and expectations with respect to a wide range of business conduct, including preparation and maintenance of financial and accounting information, compliance with laws and conflicts of interest.

Under our Code of Business Conduct and Ethics, each of our employees, officers and directors is required to report suspected or actual violations to the extent permitted by law. In addition, we have adopted separate procedures concerning the receipt and investigation of complaints relating to accounting or audit matters. These procedures have been adopted and are administered by our audit committee.

Our Code of Business Conduct and Ethics is available on our website at www.servicesource.com in the Corporate Governance section of our investor relations webpage. We will disclose on our website any amendments to the Code of Business Conduct and Ethics, as well as any waivers of the Code of Business Conduct and Ethics, that are required to be disclosed by the rules of the SEC or NASDAQ.

Considerations in Identifying and Evaluating Director Nominees

In its evaluation of director candidates, including the members of the board of directors eligible for re-election, our nominating and corporate governance committee will consider the following:

Our nominating and corporate governance committee requires the following minimum qualifications to be satisfied by any nominee for a position on the board:

If our nominating and corporate governance committee determines that an additional or replacement director is required, the nominating and corporate governance committee may take such measures as it considers appropriate in connection with its evaluation of a director candidate, including candidate interviews, inquiry of the person or persons making the recommendation or nomination, engagement of an outside search firm to gather additional information, or reliance on the knowledge of the members of the nominating and corporate governance committee, board or management.

Process for Recommending Candidates to the Board of Directors

Our nominating and corporate governance committee is responsible for, among other things, determining the criteria for membership to our board of directors and recommending candidates for election to the board of directors.

It is our nominating and corporate governance committee’s policy to consider candidates recommended by such stockholders in the same manner as candidates recommended to the committee from other sources. See “Shareholder Proposals – Director Candidate Recommendations and Director Candidate Nominations.”

Director Attendance at Annual Meetings

Although we do not have a formal policy regarding attendance by members of our board of directors at annual meetings of stockholders, we encourage, but do not require, directors to attend. The 2017 Annual Meeting of Stockholders was attended by Messrs. Carrington and Moore.

COMPENSATION OF NON-EMPLOYEE DIRECTORS

Compensation Policy

Each independent director receives the following compensation for board services:

The initial restricted stock unit (“RSU”) grant noted above has a three-year annual vesting schedule, and the annual grants have a one-year vesting schedule. The number of shares subject to these grants is based on the 90-day average price prior to the board member’s appointment or the annual shareholder meeting, as applicable.

Pursuant to this policy, in May 2017, we granted 35,251 RSUs to each of Messrs. Ashe, Cakebread, Dunlevie, Madden, Mendoza, Moore and Reynolds under our 2011 Equity Incentive Plan. Also, pursuant to this policy, in October 2017, we granted 96,802 and 97,467 RSUs to Ms. Ranganathan and Mr. Walker, respectively, upon their joining of the board of directors, as our new director initial RSU grant. In addition, upon Ms. Ranganathan’s and Mr. Walker’s joining of the board of directors, we made a grant of 21,780 and 21,930 RSUs, respectively, as a pro-rata portion of the annual director RSU grant.

In addition, we reimburse non-employee directors for travel, lodging and other reasonable expenses incurred in connection with their attendance at board or committee meetings.

The 2011 Equity Incentive Plan provides that in the event we merge with or into another corporation or undergo a change of control, as defined in the 2011 Equity Incentive Plan, the successor corporation or its parent or subsidiary may assume or substitute an equivalent award for each outstanding award under the 2011 Equity Incentive Plan. If there is no assumption or substitution of the outstanding award, or if the director is terminated or asked to resign by the successor corporation, then all outstanding but unvested awards will become fully vested and exercisable.

2017 Director Compensation

The following table sets forth information regarding compensation paid or accrued for services rendered to us by our non-employee directors during the year ended December 31, 2017.

The aggregate number of shares subject to outstanding stock options and restricted stock units at December 31, 2017 for each non-employee director was as follows:

PROPOSAL NUMBER 1 Election  Of Class I Directors

Board Structure

Our board of directors is currently composed of eight members and is divided into three staggered classes of directors. Currently, at each annual meeting of stockholders, a class of directors will be elected for a three-year term to succeed the class of directors whose terms are then expiring. The terms of the directors will expire upon the election and qualification of successor directors at the annual meetings of stockholders to be held during the years 2018 for the Class I directors (who are up for re-election at this year’s annual meeting), 2019 for the Class II directors, and 2020 for the Class III directors. If the declassification proposal is approved (Proposal 2), all members of our board of directors whose terms do not expire at the 2019 annual meeting have agreed to resign and immediately be reappointed to a term expiring at the 2019 annual meeting.

Our bylaws provide for a majority voting standard for the election of directors in uncontested elections. In order for a nominee to be elected in an uncontested election, the number of votes cast “for” such nominee’s election must exceed the number of votes cast “against” that nominee. Broker non-votes and abstentions will have no effect on the outcome of the election. This majority voting standard includes a director resignation policy in the event such nominee does not receive majority support of the votes cast.

Information Regarding our Class I Director Nominees

Our nominating and corporate governance committee recommended, and our board of directors nominated, Robert G. Ashe, Bruce W. Dunlevie and Barry D. Reynolds as nominees for election as Class I directors at the 2018 annual meeting to hold office for a three-year term until our annual meeting of stockholders to be held in 2021.

Messrs. Ashe, Dunlevie and Reynolds have agreed to serve if elected, and management has no reason to believe that either nominee will be unavailable to serve. In the event one of the nominees is unable or declines to serve as a director at the time of the 2018 annual meeting, proxies will be voted for any nominee who may be proposed by the nominating and corporate governance committee and designated by the present board of directors to fill the vacancy.

Robert G. Ashe

Bruce W. Dunlevie

Barry D. Reynolds

Information Regarding our Class II and Class III Directors

The following table sets forth the names, ages and positions of our Class II and Class III directors as of March 14, 2018:

Thomas F. Mendoza

Gary B. Moore

Christopher M. Carrington

Madhu Ranganathan

Richard G. Walker

Required Vote

If a quorum is present, our Class I directors elected to the board of directors will each be elected by a vote of the majority of the votes cast. A majority of the votes cast means the number of votes cast “FOR” such nominee’s election exceeds 50% of the number of votes cast with respect to that nominee’s election.

You may vote “FOR,” “AGAINST,” or “ABSTAIN” with respect to each director nominee. Broker non-votes and abstentions will have no effect on the outcome of the election, although they will be counted for purposes of determining whether there is a quorum. Shares represented by executed proxies will be voted, if authority to do so is not expressly withheld (as indicated on the proxy card), for the election of Messrs. Ashe, Dunlevie, and Reynolds.

Recommendation

Our board of directors recommends a vote “FOR” the election to the board of directors of each of Robert G. Ashe, Bruce W. Dunlevie, and Barry D. Reynolds as a Class I director.

PROPOSAL NUMBER 2 VOTE TO AMEND OUR CERTIFICATE OF INCORPORATION TO DECLASSIFY OUR BOARD OF DIRECTORS

Based on investor feedback, the board of directors recommends that our stockholders approve an amendment to our certificate of incorporation to declassify the board of directors and provide that all directors elected at or after our 2019 annual meeting of stockholders be elected on an annual basis. The text of the amendment, marked to show the proposed deletions and insertions, is attached as Appendix A to this proxy statement.

Since our initial public offering in 2011, we have had our classified board structure. However, the board of directors recognizes that our classified board structure does not enable stockholders to express a view on each director’s performance by means of an annual vote and therefore may be perceived as reducing directors’ accountability to stockholders. In determining to recommend the declassification of our board of directors, the board carefully considered the advantages and disadvantages of the current classified board structure and determined that it is advisable and in the best interests of the Company and our stockholders to recommend the change to declassify our board of directors.

Currently, Article VI of our certificate of incorporation provides that the board of directors shall be classified into three classes with each class holding office for a three-year term. If our stockholders approve the declassification amendment to our certificate of incorporation set forth on Appendix A of this proxy statement (the “declassification amendment”), our directors would be elected to annual terms beginning at our 2019 annual meeting of stockholders. The declassification amendment will become effective upon the filing of the amendment to our certificate of incorporation with the Delaware Secretary of State. Under Delaware law, the declassification amendment will not operate to remove a director or shorten the term of a director. If the declassification amendment is approved, and once the certificate of amendment is filed with the Delaware Secretary of State, each member of our board of directors whose term does not expire at our 2019 annual meeting (i.e., the Class I and Class III directors) will resign and be immediately re-appointed to a term that expires at our 2019 annual meeting. All eight directors will thereafter stand for election for one-year terms beginning at our 2019 annual meeting.

This description of the proposed amendments to our certificate of incorporation is only a summary of these amendments and is qualified in its entirety by reference to the actual text of Article VI as set forth on Appendix A.

Required Vote

The affirmative “FOR” vote of 66-2/3 percent of the shares present, represented and entitled to vote on the proposal is required to approve the declassification amendment to our certificate of incorporation. You may vote “FOR,” “AGAINST” or “ABSTAIN” on this proposal. Abstentions and broker non-votes have the same effect as a vote against the proposal. Unless marked to the contrary, executed proxies received will be voted “FOR” Proposal 2.

Recommendation

Our board of directors recommends a vote “FOR” the approval of the declassification amendment to our certificate of incorporation, as disclosed in this proxy statement.

PROPOSAL NUMBER 3 ADVISORY VOTE ON EXECUTIVE COMPENSATION

As required under Section 14A of the Exchange Act, we are asking our stockholders to approve, on an advisory basis, the compensation of our named executive officers as described in this proxy statement. This proposal, commonly known as a “say-on-pay” proposal, gives our stockholders the opportunity to express their views on the compensation of our named executive officers.

The say-on-pay vote is advisory, and therefore not binding on us or our compensation committee or board of directors. The say-on-pay vote will, however, provide information to us regarding investor sentiment about our executive compensation philosophy, policies and practices, which our compensation committee will be able to consider when determining executive compensation for the remainder of the current fiscal year and beyond. Our board of directors and compensation committee value the opinions of our stockholders. To the extent there is any significant vote against the named executive officer compensation disclosed in this proxy statement, we will consider our stockholders’ concerns and our compensation committee will evaluate whether any actions are necessary to address those concerns.

The advisory say-on-pay vote historically has been held annually, and the Company anticipates that the next advisory say-on-pay vote will occur at the 2019 annual meeting.

Compensation Philosophy and Programs

Our executive compensation programs are designed to attract, retain and motivate top-level executive talent and to provide compensation levels and structures that are both fiscally responsible and competitive within our industry and geography. Through our compensation programs, we strive to create a culture in which executive compensation aligns with our pay-for-performance business model by rewarding our executives for results that benefit us, our customers and our stockholders. In line with our overall pay-for-performance philosophy, our practice has been to make a significant portion of an executive’s total compensation performance-based, so that the executive will be rewarded through bonuses and equity if we perform well in the near term and over time. Please refer to the “Executive Compensation – Compensation Discussion and Analysis” section for a detailed discussion of out executive compensation practices and philosophy.

Our board of directors believes that our current executive compensation program has been effective at linking executive compensation to our performance and aligning the interests of our named executive officers with those of our stockholders. We are asking our stockholders to indicate their support for the compensation of our named executive officers as described in this proxy statement by voting in favor of the following resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion & Analysis, compensation tables, and narrative discussion in the Company’s proxy statement, is hereby APPROVED.”

Required Vote

The affirmative “FOR” vote of a majority of the shares present, represented and entitled to vote on the proposal is required to approve, on an advisory basis, the compensation awarded to named executive officers for the year ended December 31, 2017. You may vote “FOR,” “AGAINST” or “ABSTAIN” on this proposal. Abstentions have the same effect as a vote against the proposal. Broker non-votes are not deemed to be votes cast, are not included in the tabulation of voting results on this proposal, and will not affect the outcome of voting on this proposal. Unless marked to the contrary, executed proxies received will be voted “FOR” Proposal 3.

Recommendation

Our board of directors recommends a vote “FOR,” on an advisory basis, the approval of the compensation of each named executive officer, as disclosed in this proxy statement.

PROPOSAL NUMBER 4 ADVISORY VOTE ON THE FREQUENCY OF THE ADVISORY VOTE ON EXECUTIVE COMPENSATION

As required under Section 14A of the Exchange Act, every six years, stockholders are required to have the opportunity to vote, on advisory basis, on their preference of how often we hold an advisory vote to approve the compensation of our named executive officers. Under this proposal, commonly known as a “say-on-frequency” proposal, our stockholders may indicate whether they would prefer an advisory say-on-pay vote every 1 year, every 2 years, every 3 years, or they may abstain from voting. At our 2012 annual meeting of stockholders, our board of directors recommended, and our stockholders approved, on an advisory basis, that we hold our say-on-pay vote every year. Our board of directors recommends that stockholders vote on say-on-pay every year.

The say-on-frequency vote is advisory, and therefore not binding on us or our compensation committee or board of directors. Our board of directors and compensation committee value the opinions of our stockholders, but they may determine that it is in the best interests of the stockholders and the Company to hold an advisory say-on-pay vote more or less frequently than the option preferred by the stockholders. Our board of directors believes that our current practice of holding an advisory say-on-pay vote every year has been an effective in allowing our stockholders to provide us with their direct input on our executive compensation philosophy, policies and practices as disclosed in the proxy statement every year. Therefore, we are asking our stockholders to indicate their support for holding our say-on-pay vote every year.

The next advisory say-on-frequency vote will occur no later than at our 2024 annual meeting.

Required Vote

The option of “1 YEAR,” “2 YEARS,” or “3 YEARS” that receives the highest number of votes cast by stockholders will be the frequency for the advisory say-on-pay vote recommended by stockholders. You may vote for “1 YEAR,” for “2 YEARS,” or for “3 YEARS” or “ABSTAIN” on this proposal. Abstentions have the same effect as a vote against the proposal. Broker non-votes are not deemed to be votes cast, are not included in the tabulation of voting results on this proposal, and will not affect the outcome of voting on this proposal. Unless marked to the contrary, executed proxies received will be voted for “1 YEAR” on Proposal 4.

Recommendation

Our board of directors recommends a vote for “1 YEAR” for the advisory vote on the frequency of holding our say-on-pay vote, as disclosed in this proxy statement.

PROPOSAL NUMBER 5 RATIFICATION OF SELECTION OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Our audit committee has selected Ernst & Young LLP as the independent registered public accounting firm to audit our consolidated financial statements for the year ending December 31, 2018. From January through December 2017, Ernst & Young LLP served as our independent registered public accounting firm and also provided certain audit-related services. The selection of Ernst & Young LLP as our independent registered public accounting firm was ratified by our stockholders at our 2017 annual meeting. Prior to Ernst & Young LLP, PricewaterhouseCoopers LLP served as our independent registered public accounting firm through May 5, 2016 and also provided certain audit-related services.

From January 1, 2016 through May 5, 2016, there were no disagreements with PricewaterhouseCoopers LLP on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which disagreements if not resolved to the satisfaction of PricewaterhouseCoopers LLP would have caused them to make reference to the subject matter of such disagreements in their reports on the Company’s consolidated financial statements for such years, and during such period, there were no reportable events as defined in Item 304(a)(1)(v) of Regulation S-K.

Notwithstanding the audit committee’s selection of Ernst & Young LLP – and even if our stockholders ratify the selection – our audit committee, in its discretion, may appoint another independent registered public accounting firm at any time during the year if the audit committee believes that such a change would be in our best interests and in the best interests of our stockholders. Our audit committee is submitting the selection of Ernst & Young LLP to our stockholders because we value our stockholders’ views on our independent registered public accounting firm and as a matter of good corporate governance. If the appointment is not ratified by our stockholders, our audit committee may reconsider whether it should appoint another independent registered public accounting firm.

Representatives of Ernst & Young LLP are expected to attend the annual meeting, where they will be available to respond to appropriate questions and, if they desire, to make a statement.

Required Vote

Ratification of the selection of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2018 requires the affirmative “FOR” vote of a majority of the shares present, represented, and entitled to vote on the proposal. You may vote “FOR,” “AGAINST” or “ABSTAIN” from voting on this proposal. Abstentions have the same effect as a vote against the proposal. Unless marked to the contrary, executed proxies received will be voted “FOR” Proposal 5.

Recommendation

Our board of directors recommends a vote FOR the ratification of the selection of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the year ending December 31, 2018.

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Principal Accounting Fees and Services

The following table sets forth the aggregate fees for audit services provided by Ernst & Young LLP for the years ended December 31, 2017 and December 31, 2016.

Pre-Approval of Audit and Non-Audit Services

Our audit committee pre-approves all audit and permissible non-audit services provided by the independent registered public accounting firm. These services may include audit services, audit-related services, tax services and other services. The audit committee pre-approves services provided by the independent registered public accounting firm pursuant to its audit committee charter.

Report of the Audit Committee

The audit committee assists the board of directors in fulfilling its oversight responsibility over our financial reporting process. It is not the duty of the committee to plan or conduct audits or to prepare our financial statements. Management has the primary responsibility for preparing the financial statements and assuring their accuracy, effectiveness and completeness. Management is also responsible for the reporting process, including the system of internal controls. The independent registered public accounting firm is responsible for auditing our financial statements and internal control over financial reporting and expressing its opinion as to whether the statements present fairly, in accordance with accounting principles generally accepted in the United States, our financial condition, results of operations and cash flows. However, the audit committee does review and discuss the financial statements with management and the independent registered public accounting firm prior to the presentation of financial statements to our stockholders and, as appropriate, initiates inquiries into various aspects of our financial affairs.

Unless the committee has reason to question its reliance on management or the independent registered public accounting firm, the members of the committee necessarily rely on information provided to them by and on the representations made by management and the independent registered public accounting firm. Accordingly, the audit committee’s oversight does not provide an independent basis to determine that management has applied appropriate accounting and financial reporting principles. Furthermore, the audit committee’s authority and oversight responsibilities do not independently assure that the audits of our financial statements have been carried out in accordance with the standards of the Public Company Accounting Oversight Board or that the financial statements are presented in accordance with accounting principles generally accepted in the United States.

In this context, the committee has met and held discussions with management and the independent registered public accounting firm to review our audited 2017 consolidated financial statements (including the quality of our accounting principles). Management represented to the committee that our consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States, and the

committee consulted with management and the independent registered public accounting firm prior to approving the presentation of the audited 2017 consolidated financial statements to stockholders. The committee discussed with the independent registered public accounting firm the matters required to be discussed by Auditing Standard No. 16, Communications with Audit Committees, issued by the Public Company Accounting Oversight Board in Rule 3200T.

The audit committee has discussed with the independent accountant the independent accountant’s independence from us and our management. As part of that review, the committee received the written disclosures and letter required by the applicable requirements of the Public Company Accounting Oversight Board regarding the independent accountant’s communications with the audit committee concerning independence. Based on the reviews and discussions referred to above, the audit committee recommended to the board, and the board approved, our audited consolidated financial statements for the year ended December 31, 2017 for filing with the Securities and Exchange Commission as part of the Company’s Annual Report on Form 10-K. The committee has selected Ernst & Young LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2018.

Members of the Audit Committee

Madhu Ranganathan (Chair)

Robert G. Ashe

Gary B. Moore

The Report of the Audit Committee does not constitute soliciting material and shall not be deemed to be filed or incorporated by reference into any other filing by ServiceSource under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except to the extent ServiceSource specifically incorporates the Report of the Audit Committee by reference therein.

EXECUTIVE OFFICERS

The names of our executive officers, their ages, their positions with us, and other biographical information as of March 14, 2018, are set forth below. There are no family relationships among any of our directors or executive officers.

Christopher M. Carrington

Brian J. Delaney

Robert N. Pinkerton

EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

The Compensation Discussion and Analysis describes and analyzes our executive compensation philosophy and program in the context of the compensation paid during the last fiscal year to our Chief Executive Officer, our Chief Operating Officer, and out Chief Financial Officer (collectively referred to as our “named executive officers”) during 2017. Our named executive officers for 2017 are:

This Compensation Discussion and Analysis is organized as follows:

Table of Contents

The following discussion and analysis of compensation arrangements of our named executive officers for 2017 should be read together with the compensation tables and related disclosures presented below. This discussion contains forward-looking statements that are based on our current plans, considerations, expectations and determinations regarding future compensation programs.

Objectives and Principles of Our Executive Compensation

Our compensation philosophy is based on the following objectives and principles:

2017 Compensation and Corporate Governance Highlights

We endeavor to maintain strong governance standards in our executive compensation related corporate governance policies and practices. Below is a summary of key executive compensation and corporate governance practices in place during 2017. Following that is a summary of certain other practices that, because we have not considered them to effectively drive long-term stockholder value, we have not implemented.

What We Do

What We Do Not Do

Compensation Decision Process

Role of the Board of Directors and Compensation Committee. The role of our compensation committee is to oversee our executive plans and policies, administer our equity plans and approve all compensation for our named executive officers. For a description of the composition of our compensation committee, see “Corporate Governance and Board of Directors – Board Committees – Compensation Committee.”

Role of Executive Officers. Our compensation committee generally seeks input from our Chief Executive Officer and our Head of Global Human Resources when discussing executive performance and compensation levels for named executive officers (other than their own compensation). Our Head of Global Human Resources has the responsibility of advising the compensation committee and coordinating with any third-party compensation advisors. The compensation committee also works with our Chief Financial Officer to evaluate the financial, accounting and tax implications, and with our General Counsel who advises on legal matters, regarding our various compensation programs. None of our named executive officers participates in deliberations regarding his or her own compensation. Our compensation committee charter also specifies that our compensation committee deliberates and determines compensation decisions related to our Chief Executive Officer in executive session, outside of the presence of the Chief Executive Officer.

Role of Compensation Advisors. Our compensation committee has the authority to engage its own advisors to assist in carrying out its responsibilities. In prior years, our compensation committee retained an independent compensation consulting firm to provide advice to the compensation committee with respect to executive compensation decisions and comparison benchmarking. Because an independent compensation consultant provided analysis to the compensation committee in third quarter 2016, our compensation committee did not engage a third-party compensation advisor in 2017. Our compensation committee intends periodically to review the need to independently retain a compensation consultant.

2017 Advisory Vote on Executive Compensation. The advisory vote on executive compensation at our 2017 annual meeting received a favorable vote of 82% of votes cast by our stockholders. The compensation

committee is committed to ensuring that our compensation programs are consistent with our pay-for-performance philosophy and deliver appropriate results given financial performance and business conditions. The compensation committee considers both the results of the annual advisory vote and any feedback from institutional investors in making compensation decisions. Stockholder feedback will remain an important input into the compensation committee’s work on the compensation programs for us.

Benchmarking. Given that we compete for executive officer talent with companies in the technology sector and companies that provide other professional services, we relied on certain compensation benchmarking in making our compensation decisions. To determine what constitutes competitive compensation, our compensation committee:

The compensation committee considered compensation data and practices at public technology companies comparable to us with respect to size, complexity, financial performance and stage of development, ultimately considering two different groups of peer companies: one group of peers for benchmarking compensation levels, and another, larger group of peers for benchmarking compensation design. These peer company groups were selected at the time as they had similar financial size and valuation range relative to ServiceSource, and included industry classifications of IT Services and Professional Services.

The resulting peers used in our compensation benchmarking include the following:

We did not automatically tie compensation to a benchmark level for each member of our executive management team. Rather, we considered a number of individualized factors that are unique to our business, including individual performance, skill set, industry knowledge and experience, prior employment history, compensation at previous companies, recruiting efforts and negotiations, retention risk and an executive’s overall compensation level relative to his or her peers.

Our Compensation Program

The four elements of our executive compensation package are:

We view these components of compensation as related in reviewing the total compensation packages of our executive officers. We determine the appropriate level for each compensation component based in part, but not exclusively, on information from analysis of third-party compensation surveys consistent with our recruiting and retention goals, our view of internal equity and consistency and overall Company and individual performance.

We compete with many other companies in seeking to attract and retain a skilled workforce, particularly companies in the technology sector. We have not adopted any formal or informal policies or guidelines for allocating compensation between long-term and currently paid-out compensation, between cash and non-cash compensation or among different forms of non-cash compensation. However, in line with our overall pay-for-performance philosophy of rewarding our employees for results that benefit us and our customers, the compensation committee’s practice has been to make a significant portion of an employee’s total compensation performance-based, so that the employee will be rewarded through bonuses and equity if we perform well in the near term and over time.

On-Target Earnings – Base Salary and Variable Incentive Cash Compensation

When analyzing the cash compensation of our executive leadership team, we view the total cash compensation of base salary plus the variable incentive plan compensation as the on-target earnings for each of such executive officers.

In analyzing the total cash compensation, we assume that we will meet the targets necessary for our executives to earn their on-target bonuses. We analyze on-target cash earnings as the benchmark by which to measure our named executive officers’ compensation compared to the comparable positions of our peer companies. When the executive compensation was last benchmarked, in the third quarter of 2016, the target compensation opportunity for each of our named executive officers was at or above the fiftieth percentile, in each case comparing such executive’s on-target cash earnings to our peer companies. We did not change our named executive officers’ target compensation opportunity in 2017. Given our age as a Company, our size and our results of operations, and the competitive market for high-caliber executive talent – particularly in certain strategic roles – we believe that the on-target earnings for our named executive officers were reasonable and appropriate for 2017.

Base Salary. We establish base pay that we believe is both reasonable and competitive in relation to the market, including the benchmarking data described above. We regularly monitor competitive base pay levels and adjust base pay as appropriate. In general, a named executive officer’s base pay level should reflect the executive’s overall performance and contribution to us over time. We also seek to structure competitive base pay for our named executive officers based upon applicable market data analysis. As described below, we design base pay to provide the ongoing reward for each named executive officer’s work and contribution and to be competitive in attracting or retaining the executive. We do not provide automatic salary increases for our executive team.

Once base pay levels are initially determined, we conduct salary reviews based upon current market data and the executive’s specific performance achievements. We also take into account salary levels for their retention effect. Salaries are also determined based on negotiations with our executive officers, in particular when we are trying to hire a new executive officer and we must be competitive. We believe this pay-for-performance approach reflects our cultural values and our business model.

The following are the effective annual base salaries for each of our named executive officers for 2015, 2016 and 2017:

In third quarter 2016, in part in order to support executive management retention, we evaluated the overall market competitiveness of our executive compensation in comparison to our peer group. Based on that evaluation, we approved an increase in the base salaries of our named executive officers that took effect September 2, 2016. Our compensation committee determined that the base salaries in effect on December 31, 2016, also were appropriate levels for our named executive officers in fiscal 2017.

Variable Pay. Consistent with our pay-for-performance philosophy, we link a significant portion of our named executive officers’ cash compensation to individual and Company performance. We design our variable pay programs to provide reasonable and competitive earnings potential relative to our industry and geography. For our named executive officers, we have implemented our corporate incentive bonus program as a motivational tool to achieve and exceed individual and Company goals by paying for outstanding results. We base our variable pay programs on a formulaic assessment of our financial and other performance, as well as considering an assessment of each individual’s performance. We design our programs to avoid entitlements, and to align actual payouts with actual results based on clearly understood metrics.

Our compensation committee reviews the structure and design of our variable pay plans on an annual basis, typically at the beginning of each year. The overall business plan and related goals of our variable pay plans are determined at the start of the year, typically in February.

Corporate Incentive Plan – 2017

In March 2017, our compensation committee approved the 2017 bonus targets under our Corporate Incentive Plan (the “CIP”). The CIP applies to certain non-commissioned employees, including our named executive officers.

For each of the named executive officers participating in the CIP, 2017 bonus targets were set as a fixed amount, which, as a percentage of base salary, ranged from 80% to 90%.

The target bonuses for our named executive officers at 100% achievement in 2017 under the CIP, as well as the actual bonuses paid to our named executive officers in 2018 for 2017 performance, are set forth below:

For our named executive officers, the CIP bonus for 2017 was paid in one annual payment after determination of the achievement of our performance targets (which occurred in 2018). Funding for the CIP bonus pool for 2017 was based upon our achieving two targets: Revenue and EBITDA margin. The weighting for each target was 50%, as further detailed below.

Revenue and EBITDA Targets for Corporate Incentive Plan (CIP) – 2017

As noted above, during 2017, we were below the Revenue target by 7.3%, and we exceeded the EBITDA target by 52.9%. We believe the disclosure of the actual 2017 Revenue and EBITDA targets would cause competitive harm to us. We believe these targets were challenging because they required meaningful growth and success throughout our business for 2017. Under the CIP, each named executive officer was subject to a subjective personal modifier, determined by our compensation committee, which, based on 2017 actual performance, was 100% for our chief executive officer and for our chief operating officer and chief financial officer, were 100% and 100% respectively, resulting in the total CIP bonus payments, which were made in March 2018 and are described above.

Corporate Incentive Plan – 2018

On March 19, 2018, our compensation committee approved the 2018 bonus targets under our CIP. For each of the named executive officers participating in the CIP, 2018 bonus targets were set as a fixed amount, which, as a percentage of base salary, ranged from 80% to 90%.

The target bonuses for our named executive officers at 100% achievement in 2018 under the CIP are set forth below:

Revenue and EBITDA Targets for Corporate Incentive Plan (CIP) – 2018

We believe the disclosure of the actual 2018 Revenue and EBITDA targets would cause competitive harm to us. We believe these targets are challenging because they require meaningful growth and success throughout our business for 2018. Under the CIP, each named executive officer will be subject to a subjective personal modifier, as determined by our compensation committee when it determines the achievement of the performance targets for the 2018 fiscal year, on the date the Company files its Annual Report on Form 10-K for the 2018 fiscal year.

Equity-Based Rewards

We design our equity programs to be both responsible and competitive in relation to the market. We monitor the market and applicable laws and regulations and adjust our equity programs as appropriate. Restricted stock units are designed to reflect and reward a high level of sustained individual performance over time, as reflected in improved overall Company value. As described in more detail below, we design equity-based compensation to help retain talent over a period of time and to provide named executive officers with a long-term reward that aligns their interests with those of our stockholders.

Equity grants to our named executive officers are intended to ensure that equity compensation remains competitive within our industry group and geography. We consider a number of factors to determine the size of all equity grants, including competitive market factors, named executive officer performance, retention value and a review of the named executive officer’s overall compensation package. In addition, our compensation committee regularly reviews equity utilization, overhang and burn rate both as compared to prior years and as compared to our peers. Named executive officers whose skills and results we deem essential to our long-term success are eligible to receive higher equity grants. The decision to make such grants has traditionally been based on rewarding performance, consistent with our pay-for-performance philosophy, and the equity ownership of our named executive officers in relation to the market surveys, taking into account the number of vested stock options and restricted stock units that our named executive officers hold, the strategic importance of the particular executive to our business, and the overall situation of our Company. Our compensation committee makes all equity grants.

Currently, we have no policy in place that requires us to grant equity-based compensation on specified dates. Our compensation committee reviews equity compensation for incumbent executives annually, typically in February or March of each year.

Restricted Stock Units. We use restricted stock units as the primary vehicle for equity compensation. Restricted stock units have the benefit of reducing the dilution associated with our equity compensation programs,

because we are able to grant fewer shares of stock but still incent our executive officers as the values of the restricted stock units are tied to the price of the Company’s common stock and thus aligned with stockholder interests. We have typically issued our restricted stock units subject to a four-year vesting schedule. Under the vesting schedule, the restricted stock units vest in four equal annual installments beginning on a specified vesting commencement date. In September 2016, we began granting our named executive officers restricted stock units with a performance-based component as well as a time-based component to further align compensation with stockholder interests. These performance-based grants are described in more detail below.

Grant of Performance-Based Restricted Stock Units – 2017

On April 4, 2017 (the “Grant Date”), our compensation committee approved a grant of performance-based restricted stock units, or PSUs, to our named executive officers that include performance-based achievement metrics as well as a service-based vesting schedule. The target number of PSUs subject to the grant, as well as the maximum number of PSUs eligible to vest pursuant to the service-based vesting provision assuming maximum achievement of both performance-based achievement metrics, are set forth below.

The performance-based conditions are the Company’s Revenue and EBITDA performance in fiscal year 2017 as compared to the target Revenue and EBITDA approved by the board of directors, as set forth below. Half of the target number of PSUs are subject to the Revenue performance achievement, and half of the target number of PSUs are subject to the EBITDA performance achievement. The achievement of the performance targets were determined on the date the Company filed its Annual Report on Form 10-K for the 2017 fiscal year.

For each performance metric, if the applicable achievement falls between any of the thresholds, the number of PSUs that become eligible to vest for such performance metric will be determined by linear interpolation.

Under the service-based vesting condition, 50% of the PSUs that have become eligible to vest will vest on April 4, 2018, and 50% of the PSUs that have become eligible to vest will vest on April 4, 2019, which are the first and second anniversaries of the Grant Date, except as otherwise provided under certain termination and change of control provisions set forth in the 2011 Equity Incentive Plan.

For additional information on the equity-based rewards granted to our named executive officers, please see the “Grants of Plan-Based Awards” table.

Grant of Performance-Based Restricted Stock Units – 2018

On March 19, 2018 (the “Grant Date”), our compensation committee approved a grant of PSUs to our named executive officers that include performance-based achievement metrics as well as a service-based vesting schedule. The target number of PSUs subject to the grant, as well as the maximum number of PSUs eligible to vest pursuant to the service-based vesting provision assuming maximum achievement of both performance-based achievement metrics, are set forth below.