Starting Wednesday, users will begin seeing a Subscribe button alongside the “Message” and “Poke” button on Facebook profiles. In a lot of ways, it’s like following somebody on Twitter.
This button works a bit differently based on whether you’re looking at a friend’s profile. If you subscribe to the profile of somebody who is not your friend, you will get access to his or her public status updates in your News Feed. You can fine tune what type of updates you see. For example, you could subscribe to my Facebook Page and choose only to see my status updates and ignore my game or photo updates.
If the user is your friend, subscribing gives you the ability to granularly control how much of his or her content enters your stream.