Good news for mobile marketers, the time may soon be ripe for mobile ads to take in the big bucks. According to BIA’s Kelsey Group, U.S. mobile search advertising revenues are forecasted to grow from $39 million in 2008 to $2.3 billion by 2013, according to BIA’s Kelsey Group. That is a compound annual growth of 125.6.

Right now 5.2 million people in the U.S. have regular mobile Internet access. By 2013, it is predicted that 56 million people will have the same access.

Earlier this year, the Kelsey Group predicted that the market would hit $1.3 billion in 2013. So what’s with two months and $1 billion extra in predicted growth?

“The attendant increase in searches per user and the percentage of search results that are served with ads will drive the growth in mobile search ad revenues,” said Neal Polachek, chief executive officer, BIA’s The Kelsey Group.

BIA/Kelsey will present the forecast during “Winning Media Strategies,” its first conference to focus on the new media landscape and the opportunities for traditional media businesses and online companies, May 20-22 in Washington, D.C.