The AppStore isn't the perfect place for business. There have been many cries from developers for change and Apple has worked towards making the AppStore a better place with minor updates like separating top paid and top free apps, having top apps listed by category, etc.
Getting a little more scientific on the subject of AppStore success Pinch Media has but together a very nifty slideshow (below) of what they believe to be the secrets of AppStore succes like release timing, pricing, quality, marketing, the reviews, competitor actions, duplication, etc. Check out the Slide Show for some pretty charts and graphs. While it wont give you the perfect formula for "Making it" the Slide Show does give some good guidance in the right direction.