[DanHulton]

And of course, this whole thing ignores an entirely different entry point "Discover new app". It assumes you are specifically searching for the app in question. What the app store and it's ilk offer is exposure. Angry Birds has been near the top of the top 25 on the app store since launch, and that alone drives continuous sales.

If you're an incredibly well-selling web app, you STILL have to market and spend and shout to get yourself known. No matter how well you're doing, your word of mouth still probably doesn't beat Apple's Top 25 board.

[saurik]

The App Store offers exposure to a few hundred applications that are at the top of their category due to intentionally difficult to predict algorithms; relying on this mechanism for users discovering your app is asking for failure and makes about as much sense as making a web page and hoping that it appears on the front page of a website catalog/portal like Yahoo for the lifetime of the product. For 99.99% of the applications in the store, people are going to be finding out about it from online reviews, word of mouth, and search engines.