The new button is the latest in a series of additions to the site which have been launched this week – including a   smart lists feature and Facebook ’s new free instant messenger mobile app becoming available in the UK.

The new button, which has started appearing on every Facebook user’s page next to the ‘message’ and ‘add friend’ tabs, allows people to subscribe to other people’s public updates which will then appear in their news feeds.
Public updates are those which are not restricted by any privacy settings and can be seen by anyone online, as they are indexed by Google and stored for all to see.
Facebook said: “You’ve always been subscribed to friends. Now you can hear from journalists, celebrities, political figures and other people too. Click   the subscribe button on someone’s profile to get their public updates in   your News Feed.”
The move adds a Twitter-style functionality to the service, which has been lacking until now and moves the service on from just being a place to connect with friends – to being a place to share information with anyone.
The addition is being seen by technology experts as a direct challenge to   Twitter and an attempt to make more people share greater amounts of information publicly, rather than just with their friends on the site.
Interestingly when a Facebook user sends a friend request to another person on the site, they instantly become a subscriber to that user’s public updates –   unless the user turns the subscribe button off.
The company, which is about to have its annual developer conference, f8, on   September 22, is expected to announce a new digital music service in partnership with the likes of Spotify and Mog.