derGoldstein tips a story at AllThingsD about a study into mobile gamers' spending habits:
"[The study] provides a fairly compelling argument as to why a developer should continue to give away his or her games for free ... After evaluating the spending habits of 3.5 million consumers across both iOS and Android, Flurry found that among those who pay for in-app transactions, greater than five percent will spend more than $50, which rivals the amount paid at retail for top console and PC games."