• by Mark Walsh  @markfwal, June 8, 2010

Competition in the U.S. mobile ad market could heat up further, with international mobile ad network inMobi formally opening for business in the U.S. following a soft launch in January.

InMobi, which has established large footprints in Asia, Africa and Europe in the last three years, says it already delivers about 2 billion monthly impressions on mobile phones here. (Worldwide, the ad network sends 14.6 billion impressions.) But the company is now beginning a bigger on-the-ground push, opening a new office in San Mateo, Calif. in April, hiring sales staff and targeting North America-based advertisers and publishers.

"The U.S. market is a huge opportunity and a driving force in digital media in general, with unique competitors like Millennial Media and JumpTap focused on this market," said Anne Frisbie, vice president and managing director of North America for inMobi. That's not to mention others like Google-owned AdMob, which it already competes with outside the U.S.

She added that inMobi -- which operates offices in London, Bangalore, Mumbai and Singapore -- has waited to enter the U.S. market to help ensure its technology was "solidly road-tested" in other regions before rolling out here. The move follows a push that inMobi made earlier this year into Europe led by Rob Jonas, Google's former director of strategic partnerships for Europe, the Middle East and Africa.

Overall, inMobi says its network reaches 179 million unique visitors monthly in 100 countries.

In the U.S. so far, inMobi has hired about 10 sales and business-side staff with plans to add another five. Patricia Clark, formerly vice president of sales at 4Info, serves as head of national sales for the company in New York. Despite the dozen-plus mobile ad networks vying for market share, Frisbie believes inMobi's analytic offerings will help set the company apart from the competition.

In April, it began providing publishers with more detailed analytics including the ability to view performance by country, manufacturer and handset. The new tools are part of an upgraded inMobi dashboard that also included a new ad-filtering feature and more streamlined interface. "We've built a technology platform that has some unique components so people can discover who their customers really are," said Frisbie.

To date, inMobi has raised $7.6 million from venture investors including Kleiner Perkins, Caufield & Byers and Sherpalo Ventures.