Santiago Lema on the business of selling iPhone apps:
The average iOS user has a very short attention span and there are 200 apps that do exactly the same stuff yours does. You have to win at each step, and the decision will be made in less than 60 seconds. Whether you manage to get your app in the Top 50 rankings or your app shows up through search, the same steps apply. Bringing the user to a download amounts to convincing him to go through a series of gates, always choosing yours.
I’ve watched Santiago grow from toying with iPhone apps to making it his living over the past few years. He’s really going for the mainstream user, and has some great tips in order to reach him and secure the download.