Mobile ad network Greystripe today announced a deal with Media Networks Inc. to better sell locally targeted mobile advertising. It’s mostly a channel deal that utilizes MNI’s sales force to sell local ads on Greystripe’s mobile network.

This lets Greystripe better reach locally segmented advertisers without having to build its own sales force — quite an investment as we all know. Time Warner-owned MNI has about 60 to 70 salespeople who already sell various forms of locally targeted print and digital media.

Greystripe meanwhile reaches 30 million monthly uniques and 2,500 mobile sites and apps. It mostly focuses on national campaigns for brand advertisers like Axe, Burger King and Buick, but this deal broadens its addressable market.

Specifically, MNI works with regional and mid-market segments like insurance and education (Hofstra University, Tennessee Tourism, Blue Cross/Blue Shield of Arizona). Besides broadening the advertiser base, these are companies with local or regional advertising needs.

Meanwhile, BIA/Kelsey projects the U.S. mobile ad market to reach $1 billion this year and $2.9 billion by 2014. Location targeted ads are the fastest growing portion of that, growing from $400 million last year to just over $2 billion by 2014.

Though a growing portion of that will come from small-business advertisers, the majority of locally targeted mobile ad revenues will be mid-market and national companies that evolve their mobile campaigns. Today’s move, and others like it, should accelerate this shift.

Greystripe meanwhile continues to innovate in other ways. It’s best known for its Flash-transcoding technology, which brings “iAd-like” rich media ads to iPhone and Android. This helped boost its 2010 year-over-year revenues by 400 percent.