No matter how good your application is, no matter how novel, how brilliant, how special -- none of it matters if you don't have anyone to use it. The iOS App Store changed the way developers work by providing a streamlined channel between software developers and potential customers.
Consider my APIkit scanner application. After opening the app to public beta a few months ago, I may have gotten about 200-300 users. Total. (And a grand total of zero feedback, but that's a completely different gripe about public betas.) Contrast with App Store.
As far as I can calculate, I have now shipped well over a million apps in App Store -- that's extrapolating from the 600+ thousand copies that iTunes Connect tells me I've pushed out in the last six months, no