Brent Simmons on arguments that the App Store is great because it exposes your app to customers:
To be on the App Store is to be lost within an enormous sea of floating junk. No matter how well you do at your app description and screenshots — even if you get some kind of feature — your app will not be found by many people.
I can’t recall the last time I discovered an app on the App Store via searching. Searching doesn’t even work if you know the name of the app you’re searching for.