This move by twitter is a significant change from the usual scenario in which users see only tweets from accounts they follow as well as retweets and promoted tweets.
In the update twitter said ”Additionally, when we identify a Tweet, an account to follow, or other content that’s popular or relevant, we may add it to your timeline. This means you will sometimes see Tweets from accounts you don’t follow”
Twitter said they select each Tweet using a variety of signals, including how popular it is and how people in your network are interacting with it.
”Our goal is to make your home timeline even more relevant and interesting” the statement said.
This new feature will also mean that the tweets you favourite, will now start to appear in users’ timelines as well.