From my experience, you really don't make much on ads from apps and they tend to drive people away. To do well on mobile app ads, you need a fairly massive audi

From my experience, you really don't make much on ads from apps and they tend to drive people away. To do well on mobile app ads, you need a fairly massive audience and then you need to market your ad space directly. In particular, video ads on mobile can be very lucrative, but you'd need a very engaging app to keep people around when you start showing those kinds of ads. More than likely the reason his free app did so well against the others is that the others likely had ads or nag screens or similar, while his was genuinely free.