iPhone app "piracy" is perhaps a little different from run of the mill software copyright infringement. It's one of the only places around where even for consumers, there's no way of trying before you buy. I can imagine that there is a significant (I have no idea how large, and not a majority certainly, but significant) number of people who will pirate an iPhone app and then later buy it if they find themselves using it. I'm honest enough to admit that I do this, and I very much doubt I'm alone.