Twitter is experimenting with our timelines - something you'll know full well if you have spotted any tweets from people you don't follow recently.
Now in a blog Trevor O'Brien of Twitter has said that they plan to continue putting tweets from people users do not follow in their timelines based on signals - such as favouriting - from people users to follow, explaining:
Testing indicated that most people enjoy seeing Tweets from accounts they may not follow, based on signals such as activity from accounts you do follow, the popularity of the Tweets, and how people in your network interact with them. These experiments now inform the timeline you see today.
Things haven't completely changed and your Twitter timeline won't look like a Facebook-style newsfeed, but the company has said the Twitter timeline will continue to "evolve".