U.S. Internet advertising revenue will exceed US $35 billion by 2011, from US $12.5 billion in 2005, with a continuous two-digit annual growth, according to the research firm MultiMedia Intelligence.

Online ad revenue in the United States grew aggressively in 2005 and 2006, with a more than 30 percent annual growth rate. It slowed down in 2007 to 22 percent, and is expected to slide to around 13 and 17 percent throughout 2011.

Search, since 2005, has owned the biggest chunk of total revenue, and will maintain its place throughout 2011. Lead generation, rich media and display ads have had the greatest gain within six years, with growing more than 200 percent from 2005 to 2011.

Other categories still have growth over than 100 percent, except for sponsorship, which is expected to decrease from US $627 million in 2005 to US $292 million in 2011, dropping by 53 percent within six years, MultiMedia Intelligence reported.