Oh, to be clear I was talking about the phone. They are certainly way ahead in terms of their app store. However, I'd still bet that the number of people buying apps on Apple's store is tiny compared to the number of phone users, so there's a big 'negative space' to consider there.

Come to think of it though, in terms of buying things, the 'biggest' market is probably all those crappy ring tones and things of that ilk, although it's probably not of much interest to 'hacker news' types.