With friends not posting as much about their personal lives, Facebook found a new kind of update to stuff into the news feed: any public post a friend commented on, even if it was from someone outside their network. That increased the amount of virality on Facebook, because a person didn’t have to choose to share something in order for a wider audience to see it. At the company they called this an “edge story,” because it happened at the edge of a user’s friend circle. Again, the move helped spread political debates on Facebook.
