How do obvious scam apps make it to top 10 paid in iOS App Store?

If you've used an iPhone, you must've seen applications that claim to "improve your battery life" or "track any cell phone in the world using sophisticated government-level technology" in top positions in the store. The latter app, for instance, is a prank that only find location of your own phone.

Current top 10 includes "Fingerprint Protector," an app that claims to add a fingerprint scanner to your phone, with a long convincing description and one sentence mentioning that it's a prank. The description ends with "It works. Guaranteed 100%!!!!!!"

Usually these apps have a small number of reviews (most one star, of course.) It seems like these apps fall off (or get killed?) periodically and then come back with another name and a similar description.

In this case, a scammer is likely netting thousands $ per day while some hard-working developers on this board may be struggling to promote their apps.

Or perhaps no "blackhat" tactics are at play and the users are just gullible and buy anything that sounds catchy.

Other applications by the same developer: http://www.appannie.com/company/appforall/