mobile advertising networks
When google acquired admob for $750m it looked like the mobile advertising industry had been sewn up. Admob was by far the largest mobile ad network, and combined with google would have huge power in the market. At the same time, Apple, having acquired Quattro, another big mobile ad network, was rolling out its own iAds format, picking off the high end of mobile advertising. The only question was how quickly the remaining independent ad networks (Millenial Media, Inmobi etc) would be snapped up.
Fast forward to today and the market looks very different. There are a load of new exciting players operating in the mobile ad market, some of them making admob / Google look very much like a slow incumbent. New models such as affiliate/ CPA, incentivised downloads and direct sales are being used to bring much needed innovation into the mobile ad space.