Recently Facebook had introduced “Subscribe” for the profile page of the Facebook users.
i-e Anyone can subscribe to updates of any other person if they have allowed subscription. In otherwords we can get updates from someone even without requiring them to be our facebook friend.
It is exactly same as Twitter Follow concept.
Your friends are already subscribed to get your updates as they always have, and you, in turn, are subscribed to their updates.
If you choose to allow public subscribers, then those people will only see the content you share that is marked public.
you can read more details here.
