The little tiny games topping the free chart may not earn as much as they seem, unless they are played again and again for a long time. They should depend on clicks of mobile ads and mobile games have poor CPI ratios. Yeah. Flappy Bird has been downloaded more than a few million times and is known to garner $50,000 a day. Nice. But that would be a grand outlier and I don't think the game sustains that amount of revenue now.