For the most part, the apps in Google’s Play Store are all well made, functional tools. However, for every good app that was made by an honest developer, there are a few that are made by people with the intention of gaming the system. Those people may no longer get their way as Google has announced that it will be cracking down on these developers and their apps.
According to Google, the company mentions that they are aware of developers attempting to manipulate the placement of their apps through illegitimate means. This could mean fraudulent installs, fake reviews, and incentivized ratings. All of these, Google mentions, are in direct violation of the Google Play Developer Policy.
In order to counter these attempts, Google will be rolling out improved detection and filtering systesm to combat manipulation attempts. This system will run automatically, filtering apps that it deems fraudulent. Additionally, developers who continue to game the Play Store will have their apps taken down from Google Play.
Source: Android Developers Blog