It's worth pointing out that the app store is one of the things apple didn't get right 5 years ago. It came later, after they'd spent almost a year claiming that the proper software extension mechanism was web apps. Obviously that doesn't detract from its success, but I think it's an important part of history. The app ecosystem that we all associate with "iOS" beat Android to market by only about 6 months.

Yet 6 months was apparently enough - Apple's Appstore is still ahead.

Cell phone operators had "java stores" that were just as easy to operate (and would even just show up on your monthly bill, so no credit card needed). It's just the iPhone was the first platform good enough that people wanted to buy apps for.