Facebook is rethinking the way it decides which posts users are most likely to see. The big difference is putting more weight on how many comments a post gets rather than how many times it’s shared.

The update will affect the default News Feed that users see unless they’ve changed their settings to see all the content in chronological order and/or filtered out some types of content. The order posts appear in a News Feed is important as the sheer amount of content eligible for most users’ account means they are unlikely to scroll through everything.

While multiple factors come into play, until now this order has largely been based around the number of people who shared a post. The theory was that if people shared a post or link, they found it worthwhile and interesting, and in turn other people would do the same. One big drawback is that this doesn’t distinguish between shares that really are a recommendation and shares that are more along the lines of “have you seen this terrible/outrageous/disgusting article.” Another is that there’s also a reward for clickbait headlines that are so dramatic some people share them without fully reading the associated article or linked page.

The revised rankings will reportedly be based more on how many comments a post or link gets. Facebook argues this is a positive for sites as users who comment on and debate a piece have a better emotional response than those who simply read content without interacting.

Again the algorithm does have its potential downsides, namely that it’s now in the interests of sites and organizations to post content that will spark lengthy back-and-forth arguments. That’s particularly the case if the algorithm is simply based on raw numbers rather than the less-quantifiable ‘quality’ and tone of debate.

There’s also the risk that less scrupulous folk could even post troll comments underneath their own content (or hire somebody to do it) in a bid to artificially extend the debate.