In online ads, it's Google, Facebook and ... who? By: CNBC.com News April 17, 2015 at 11:43 AM EDT In the battle for digital ad dollars, it's Google, Facebook and then who? That's what marketers are asking as ad dollars move to the web and mobile. Read More >> Related Stocks: Amazon.com Facebook Google, Inc. Microsoft Pandora Media Inc Thomson Reuters Corporation Truecar Inc Twitter, Inc. Volkswagen A G ADR Yahoo Yelp Inc