Most of you probably don't remember or have heard of Direct Hit, it was a search engine from the 90s. It ranked web sites based off of user metrics, mostly based off of how many times a user clicked on a search result. The search engine no longer exists.
When I read the story on Cult Of Mac named Crazy iPhone rig shows how Chinese workers manipulate App Store rankings and saw this photo, it reminded me of Direct Hit. How people use to hire cheap labor to sit at a desk with computers around them, clicking on results.
The same concept now works with ranking in App Stores. The more downloads an app gets, the better chance it has to rank well. It is not just downloads, but downloads is a major ranking factor there.
The Cult Of Mac said, "the alleged price sheet claims that a person looking to get into the top 10 free apps list is looking at spending $11,200. To stay there, they will then need to shell out $65,000 per week."
Forum discussion at Google+.