Google Admob. Google announced today it would acquire mobile display ad serving platform Admob for $750M in stock. The 3-year-old San Mateo-based startup serves ads on mobile websites and applications. Google hopes the acquisition will help them monetize the mobile web, as it penetrates the market with Android-based phones. One wonders if this could mark the beginning of a mobile ad network feeding frenzy, similar to the string of big online ad network acquisitions in 2007 that say Microsoft, Google, Yahoo, AOL buy up networks like Blue Lithium, Quigo and Tacoda.

Admob has seen significant commercial traction since its founding in 2006. Current clients include Ford Motors, Coca-Cola, Electronic Art, Procter & Gamble, MTV Europe, Adidas AG and Paramount Pictures. In August of this year, Admob acquired mobile ad exchange Adwhirl, a strategic buy that helped it stay ahead of competitors. Still, with estimates of $45-$60M in annual revenue, the valuation, which constitutes a 13-17x revenue multiple, seems a bit high.

Interestingly, AdMob is probably the biggest mobile application ad network on the iPhone. This means Google will be making money from free apps on Apple’s platform. The strategic chess move might explain the valuation—in this sense it would mirror Google’s YouTube purchase, which Eric Schmidt recently said cost them a $1 billion premium, which Google paid in order to keep competitors from snapping it up.