Phil Libin, the CEO of note taking app Evernote, is sitting on a $1 billion valuation and plans for an IPO, and while it may be a while yet before it follows through on going public , today at LeWeb in London he revealed new numbers for just how much the service is getting used, and how much money different platforms are bringing into the pot.

He said that the company now has 34 million users overall across all platforms — mobile and web — with the number of paying users now at 1.4 million: that’s a significant rise on the 25 million overall and 1 million paying users Evernote last reported as recently as May, when it announced its $70 million round.

He then did something a little atypical for a startup,which can be cagey about how much money it makes when the chief aim is to scale as much as possible. He talked about average revenues per user, on an annual basis, based on different platforms. It goes like this:

MOBILE
Android: $1.06
Windows Phone 7: $1.44
iPhone: $1.79
Blackberry: $2.01
iPad: $2.18 

DESKTOP
Desktop web $1.81
Windows PC $2.33
Mac OS $3.16 

Libin notes that he thinks that when there are fewer users the average revenues are higher, but also it may be because of the higher amount of enterprise users on platforms like RIM’s. “There are very few users on the BlackBerry platform, but they do pay,” he said.

He also notes that some developers report higher revenues for iPhone users, possibly because they do more with mobile ads around them. Evernote’s business model, he says, is about making the initial experience as inexpensive and easy to access as possible and then providing opportunities to charge in the app for extra features.

“Our philosophy is to let people buy extras as easily as they can,” he said, and in-app purchases are fine by them. “We don’t begrudge Apple their 30 percent because it’s more frictionless. People complain that in-app stuff is expensive but when you think about the massive marketing and discoverability you get from the app store, you should think of it as the transacion stuff plus marketing.”

The iPad, meanwhile, is proving yet again that it is a sticky and attractive platform for consuming content. A survey we covered yesterday from the OPA also reached a similar conclusion with respect to paid content engagement on the tablet, with 61 percent of all tablet users saying they pay for apps and other services.

He points out that Apple users are the most valuable at the moment for Evernote. Counting total user numbers and revenues, Apple platforms work out to the single biggest category. So that plays out in development, too: “It’s about half and half,” he said. “Half of our effort goes into Apple and half goes into everything else.”

He also gave some details on how the newer apps, Food, Hello and Skitch, are performing:

Food $6.73
Skitch $8.44
Hello $9.22

“Food users are the most engaged,” he said. The fact that Evernote is making such healthy revenues out of their vertical efforts could be a good sign of more of these being developed and rolled out in the months ahead. “Moving fast to offer multiple apps has paid off for us,” he notes.

He also noted that revenues from the 10 most-used third party apps is $9.53, collectively.

The role of mobile, for a company built first on a mobile app, remains strong: at the moment 75 percent of all new users are coming on via mobile, with the remaining 25 percent from desktop.

Libin, who has talked many times of wanting to build a company that is sustainable for the next 100 years, says that he wants this to translate into an actual product: a service to sell storage for 100 years, where users can designate others to access it as well. He is unfazed that in that time something better than Evernote might come along. “If someone makes a great product better than Evernote they deserve to win but I’ve not seen that yet,” he said.

Looking ahead, given how well the Food app has done, Libin wants to take some of that effectiveness and move it into new apps, specifically around photos. That’s not to say he wants to make the “next Instagram” but to incorporate more image capabilities into more places: “We’re working on making the experience better for photos. We want to use evernote for informational documents, but then with food, you can see us moving into a whole new set of products away from productivity and more into lifestyle,” he said at LeWeb. “For specific, beautiful and information-rich aspects of your life, we will provide a way to keep memories and experiences more. Expect more apps for that in the months ahead.”

[Image: Erno Hannick, Instagram]