Naturally, Facebook decided to make the changes based on yet more analytics gleaned from its "Feed Quality Program." After surveying thousands of people, the company found out that likes, sharing and comments don't tell the entire story about whether someone wants to see an article. (For those of us who almost never like, click or comment on random articles, that seems pretty obvious.) Specifically, Facebook pointed out that people often don't do anything with "articles about a serious current event, or sad news from a friend."
The goal, the company says, is to "better understand which articles might be interesting to you based on how long you and others read them, so you'll be more likely to see stories you're interested in." At the same time, it will try to avoid being repetitive by reducing how often, and how frequently, you see posts from the same publisher. Overall, this won't affect your News Feed much, as Facebook promises you may see a small increase or decrease in referral traffic. The changes will roll out over the next few weeks.