AdWhirl, formerly known as Adrollo and serves 250 million ad impressions of the top 50 Apps in the App Store monthly, revealed the success of some of the top ad-supported iPhone apps.

AdWhirl says that top apps can make $400 to $5,000 per day on ads, averaging an effective CPM (cost per 1,000 impressions) near $2. (That sounds terrible compared to a good Web site, but it’s better than Facebook or MySpace apps.)

[via Silicon Alley Insider]