If you are thinking about paid advertising to sell your new mobile game or app then you may want to think again. I came across this very informative article outlining the experiences of a real mobile game developer and would recommend it as a must read:
The article paints a VERY bleak picture of extortionate CPI advertising where the likes of Apple (yes Apple you read that correctly), are effectively charging over $60 per user acquisition. To add insult to injury the developer that got the acquisition is paid just a cent! This is not limited to just Apple, many advertises are up to the same extortionate tricks.