Mobile marketing company Swrve has released their report on 'App Monetization and Engagement'. Using a 'like for like' comparison in April, the San Francisco based company looked at the respective retention rates, engagement levels, and monetization of users, over the two leading mobile ecosystems..

http://www.forbes.com/sites/ewanspence/2014/05/21/for-mobile-monetization-choose-android-for-ads-and-apple-for-in-app-purchases/