According to this update, the Steam review system is being overhauled to prevent abuse. One of the ways Valve is combating fraudulent reviews is by not factoring in reviews written by customers that activated the game through a product key. The reviews will still be visible, but no score won’t be factored in. Over the past few months, we've been reading your feedback and reports on the Steam Customer Review System. In addition, we've been looking at the different ways customer reviews are being used on Steam and evaluating which aspects of the feature need the most improvement. In May of this year we made changes to highlight the recent reviews on games to better show the current state of quickly evolving products (read more about those changes here). Now we are releasing the next update, which adds more filtering and sorting options for the displayed reviews, and sets some new defaults to highlight the recent, helpful, and relevant reviews.