You know how Twitter started inserting others' favorites and follows into your timeline? As it turns out, it's not an experiment -- it's official policy. We now know that the social network recently updated its timeline explanation to confirm that it's adding tweets from strangers, new accounts to follow and other "popular" content to your feed. Like you might have suspected, the company is trying to make your stream "even more relevant and interesting" by showing you material you might not otherwise have seen.It's reassuring that Twitter isn't simply broadcasting everything you do. However, as Quartz notes, it still represents a big change to the way the service behaves. Outside of ads, the timeline has always focused on showing you the latest content from people you meant to follow. Now, it's a more Facebook-like experience where the company chooses a bit of what you see in an attempt to get more active users and boost its ad revenue. You shouldn't miss out on any of the action, but you may have to wade through some clutter (and become some of the clutter) to get what you want.