Facebook is on track to pass Yahoo! in US display advertising revenue this year while Google will also gain market share, according to a forecast published on Monday by digital marketing firm eMarketer. Facebook\'s share of US online display ad revenue will grow to 17.7 percent this year, up from 12.2 percent last year, while Yahoo!\'s share is expected to decline to 13.1 percent in 2011 from 14.4 percent last year, eMarketer said. Google\'s share of US display advertising revenue will grow to 9.3 percent this year from 8.6 percent last year, eMarketer said. It estimated that Facebook will bring in $2.19 billion in display ad revenue this year, up from $1.21 billion last year, while Yahoo! will account for $1.62 billion, up from $1.43 billion last year. Google\'s display ad revenue will top $1 billion for the first time this year as the Internet giant earns $1.15 billion, up from $860 million last year. Google, in a bid to boost display ad revenue, announced the acquisition last week of Admeld, a New York-based company that provides an advertising platform for publishers. The Mountain View, California-based Google makes most of its money from advertising tied to Internet search but is seeking to carve out a bigger slice of the growing display advertising pie. Display advertising includes rich media, digital video and banner ads. The Interactive Advertising Bureau and PricewaterhouseCoopers reported in April that US online advertising revenue rose 15 percent last year to a record $26 billion with display ads accounting for 38 percent of the total. EMarketer said it expects Google\'s US search advertising revenue to grow 38.9 percent to $10.92 billion in 2011. It said Google\'s share of overall US search ad revenue will grow to 75.9 percent this year, up from 73.6 percent in 2010. Microsoft\'s share of overall US search ad revenue is expected to grow to eight percent this year, up from 6.9 percent last year.