I agree Pady.
Even Apple agrees that the iTunes app store has grow to a point, which it to is hard to find good apps, hence they are sorta splinting the store up.

Anyway
Back to the basics, you can open up a shop in a strip mall with traffic of hundreds of people - or open your shop in a mega mall with traffic of millions of people.

There is a whole ecosystem at the Apples App store to get your product at the top 10 list. Not easy but a better chance than some obscure web site, even Mac Update is sorta obscure <-- keep in mind that millions of iPhone owners are NOT even Mac users, so would not even heard of Mac Update.