3 promising tech darlings that fell flat By: CNBC.com News June 13, 2014 at 12:17 PM EDT Just because an idea is smart and disruptive, doesn't mean it'll work. Here are the tales of three Silicon Valley darlings that failed to deliver. Read More >> Related Stocks: American Express Best Buy Facebook GameStop Corp Google, Inc. Groupon Cl A Microsoft Nintendo Ltd-Ord Sony Corp Starbucks Corp Yelp Inc