http://www.intomobile.com/2010/05/26/admob-metrics-for-april-android-vs-iphone/ http://www.intomobile.com/2010/05/26/admob-metrics-for-april... has some numbers

http://www.intomobile.com/2010/05/26/admob-metrics-for-april-android-vs-iphone/ http://www.intomobile.com/2010/05/26/admob-metrics-for-april... has some numbers for comparison.