Games developer says there's money in free…

We know that developers who get their apps into the top lists at the iTunes Store make oodles of cash, but as the smartphone biz expands it looks like some are making serious money.

Games developer Backflip Studios has confirmed itself to be making over half a million dollars per month from in-game ads alone. That’s on top of any revenues for games sales.

At root is the 47.5 million Backflip titles installed on iOS devices (and another 5.5 million on Androids). These form a network for advertising which is bringing in big bucks for the developer.

The developer sees up to 800 million ad impressions per month across their free titles (such as Ninjump, pictured). Revenues have expanded fast — in March the company had raised a million dollars in the previous six months.