So how much was the commission on the I am Rich"
I guess he'd lose the most...
Come to think of it, it was discussed before, that most people don't use many of their apps after the first few days, maybe even first few hours.
So, let's say there's a game on your iPhone, what would be the expected total time to finish it and get bored with it? I bet less than 90 days. So you can basically have a free game: download, finish, refund. It's golden!
In the world of "proper" computers, when was the last time you could get a full refund for a software after 90 days? In digital downloads, I don't think it ever happened. Of course, most of the time the developer cannot be sure that the person didn't make a copy of the software and send back the original copy (that is controlled in the iPhone's little walled garden). But e.g. Steam would be similarly in charge of your software - and offer no such refund...
So, if it's in the contract, well, not much to do about it. If you get bitten (more refunds than sales) think again next time how you sell your app or maybe how to make a better one that peopel actually wanna keep! If still make money, give thanks to the mighty Steve that he let you keep some, and the users don't exploit the possibilities handed to them... ;)