We already know that we only get the similar kind of content in our Facebook feed that we like/share/comment on. That's called echo effect.
But we don't always press 'like' or 'share' buttons on every post that pops up in our Facebook feed, even if we like it or care about it.
Now, Facebook would know even without any of your 'labelled' activity whether particular stuff in the News Feed interests you or not.
Facebook is tweaking its algorithms to account for a new metric: the amount of time you spend looking at things in your feed, regardless of whether or not you actively interact with it, TechCrunch reported.
Scroll past something without stopping for long, and Facebook's algorithms will slowly learn that you don't particularly care for that sort of content.
Stop on a post for a bit, and Facebook starts the timer behind the scenes. If you spend more time on this story than you spend on most things in your feed "studying a picture, perusing the comment thread " they will take that as a signal that it's something you care about.
This change allows Facebook's algorithms to take the hint without requiring you to lift a finger.
Once things shift toward passive behaviour analysis, Facebook's News Feed begins to understand what you care about more than you ever could.
Facebook said it would be introducing the algorithm tweak in the coming weeks. However, don't expect any dramatic changes to what pops up in your feed, at least not very soon. It will take some time before it actually makes an impact.
Especially, pages are not likely to see significant changes in distribution as a result of this update.