According to a report by a digital advertising research firm eMarketer, Google Inc is all set to surpass Facebook Inc in the race to be the biggest earner in the US display ads this year.

This comes as disappointing news for Facebook, as the social networking site losses out to the Web-search giant, Google, who gets distinction with 15.4 percent ad market share in the US.

This translates Google’s net display-ad revenue to $2.31 billion, up from $1.38 billion in 2011.

Meanwhile, in comparison, Facebook is expected to generate $2.16 billion in net display ad revenue this year, which accounts for 14.4 percent of the US market, just one percent less than Google.

However, the success of Google is considered due to its dominance in three top spots including Web-search ads, mobile ads, and display ads. The rising popularity of ads in YouTube and Admob has got the firm lot of clients and profit.

Google got the top spot, Facebook came second, followed by Yahoo!, Microsoft Corp. and AOL Inc.

Trying to hit off with advertising on mobile devices, the social networking site, however recently announced launching Facebook beta for mobile ad network, which would let advertisers target ads using Facebook data across the web.