There is a thread discussing i-Ad revenue here: http://forums.macrumors.com/showthread.php?t=1022402

There are a lot of mobile advertising networks. A lot of the analytics companies have ad networks connected with them (Flurry, Mobclix), a lot just are ad networks (Ad Mob, In Mobi). There are tons of advertising providers. Tons. Ask around, see who has used what and how they like them.