About 1,5 percent of all active mobile users purchase anthing. Of those, 49 percent made only a single purchase. Average in-app purchase is USD 5,94.

So, the industry´s actual revenues are more or less based on a still very small figure of active purchasers – there is much space for future development.

Full story: .15% of mobile gamers make up 50% of in-app revenue – Survey | GamesIndustry International.