Facebook Tweaks News Feed Feature to Factor Expected Reading Time

Facebook revealed on Friday that it has tweaked the stream of information you get on the service once again — this time to factor in the amount of time you spend looking at a post.
So if you spend a lot of time glancing over a News Feed post with photos from your sister's wedding, say, Facebook now notices that, factors in how long the post is on your screen, and places any other photo-based posts from your sister higher up in your News Feed.
This is also the latest in a long series of News Feed tweaks Facebook makes for accuracy and relevance. This April, for example, the social network announced it had adjusted the News Feed algorithm to emphasize updates from friends versus content from Pages.