Millions of ratings and reviews deleted from Google Play

Google this week announced that millions of ratings and reviews were deleted from Google Play. Fei Ye, Software Engineer and Kazushi Nagayama, Ninja Spamologist, at Google, says that thousands of bad apps were also identified due to suspicious reviews and rating activities on them.

Google can take action on the app itself, as well as the review or rating in question. Google says user trust is a top priority and fake and misleading reviews can undermine users' trust in ratings. Google is deleting ratings and reviews based on the following guidelines:

• Bad content: Reviews that are profane, hateful, or off-topic.
• Fake ratings: Ratings and reviews meant to manipulate an app's average rating or top reviews. We've seen different approaches to manipulate the average rating; from 5-star attacks to positively boost an app's average rating, to 1-star attacks to influence it negatively.
• Incentivized ratings: Ratings and reviews given by real humans in exchange for money or valuable items.

Since this year, Google Play Trust & Safety teams have a system that combines human intelligence with machine learning to detect and enforce policy violations in ratings and reviews.

Google is also asking developers to not buy fake or incentivized ratings, and to not run campaigns, in-app or otherwise, like "Give us 5 stars and we'll give you this in-app item!" That counts as incentivized ratings, and it's prohibited by policy.