As long as there's money to be made in apps, there will be companies trying to inflate an app's rating by faking statistics. Now, Google's taking aim at developers who try to artificially push their app up in the Play Store rankings. According to a post on Google's Android Developers Blog, the Play Store has new spam filters that will target apps that try to make themselves look better by fudging their stats. If Google thinks a developer paid someone to install their app, or they're flooding their profile with fake or incentivised reviews, they will get pushed down in the rankings. If they keep doing it, they may end up getting their apps pulled. Shady developers have tried to automate the process of getting a lot of positive reviews (for example, using Amazon's Mechanical Turk to outsource installs and reviews), but this new filter system should help make those efforts a little more worthless.
Keeping the Play Store trusted: fighting fraud and spam installs [Android Developers Blog]