AdWhirl, a platform for iPhone applications that allows developers to switch between ad networks on-the-fly, has released a report indicating that applications that crack the top 100 in the Free Apps list can make between $400-$5000 a day in advertising revenue.
Sam Yam, co-founder of the company formerly known as Adrollo, says AdWhirl has signed over 10% of the top 50 applications in the App Store to the platform and is serving 250 million ad impressions per month. AdWhirl’s platform gives developers access to multiple iPhone ad networks at once, allowing them to compensate when one network doesn’t have enough ad inventory, something Yam says happens as much as 40% of the time.
Having launched only in the last month, AdWhirl reports going rates of $1.90 eCPM (effective cost per thousand impressions) and 2.6% CTR (click-through rate), numbers that should make both advertisers and free app developers optimistic about the viability of the ad supported free app business model.