They don't have to resort to advertising so much as choosing the advertising model because it yields more revenue. At least for the specific case of Angry Birds

They don't have to resort to advertising so much as choosing the advertising model because it yields more revenue. At least for the specific case of Angry Birds. http://www.intomobile.com/2010/12/03/angry-birds-android-1-million-ad-revenue/ http://www.intomobile.com/2010/12/03/angry-birds-android-1-m...