Facebook is trying to figure out why certain posts go viral

As we work to improve News Feed, we make updates to the algorithm that help make sure you are seeing the most relevant stories at the top of your feed. We want to make sure that everyone who uses News Feed can understand what updates we’re making and the thinking behind them. That’s why we continue to publish News Feed FYI blog posts to explain major updates and how we’re working to get better at showing you the stories that matter most to you. The actions people take on Facebook—liking, clicking, commenting or sharing a post—are some of the main factors we consider to determine what to show at the top of your News Feed. We’ve learned that honing in on how to value these signals helps make sure we show you the most relevant content. As part of our ongoing effort to improve News Feed, we ask thousands of people every day to rate their experience and tell us how we can improve what they see when they check Facebook. People also take story surveys where they see two stories that could be in their News Feed and answer which they’d most want to see. We compare their answer to the order we would have put these stories in their News Feed. If the story picked is the one News Feed would have shown higher up, that’s a good sign that things are working well. If the story picked is the one we would have put lower down, this highlights an area for improvement.