Google Play has added some new language to its Developer Program Policies that concerns mobile development firms who offer incentives to users in exchange for downloading, reviewing or rating an app. "Developers must not attempt to manipulate the placement of any apps in the store," says the policy. "This includes, but is not limited to, inflating product ratings, reviews, or install counts by illegitimate means, such as fraudulent or incentivized installs, reviews and ratings."
However, the store isn't going to kick out apps automatically if they use incentives. "Whilst we won't automatically remove apps from the store just because they utilize incentivized installs as one of their user acquisition channels, we will monitor for, and take action against behavior that compromises the integrity of the store," it said. "To address those whose intent we perceive is to manipulate the placements of their apps, we will monitor and filter incentivized installs in our systems, including removal from the top charts. If warranted, identified apps also may be removed from the store."