3 years ago I bought my first Apple computer. Coming to the Apple platform, I was amazed by all the apps my fellow co-workers would buy for their Macs. Most of them were just simple stupid things that cost only a few bucks but I could never see an average non-Apple user buying. I have no statistical evidence, but it seems like Apple users are more susceptible to buying apps, ring tones, songs, and other junk. My advice would be build for the iPhone and if you get something that is very popular or making you a ton of money, then port it over.