When Apple finally announced the iPhone, many potential customers were stunned to hear that (unlike most other "smart phones") there would be no supported way to run new programs on the device. If you want to add functionality to the iPhone, the official way to do that is to make it a web application, run through a web browser. Why on earth, people were asking, would Apple cripple their own device like this?

Terms of Apple's contracts with European telecom providers for iPhone support are now public. Every time somebody runs one of those webapps, Apple gets a cut on the data traffic.