>Microsoft has to handle patch distribution, patching itself, tech support for patching, complaints and rollbacks and so on for many years after release -- remember, they still provide patches for Xbox 360 games sold in 2005!

Apple bears all the same costs for iOS and it all comes out of that same 30% fee. For free apps, they eat all those costs.

Hell, Apple provides free in-person customer support as well as support by phone.