Is it possible to be friends on Facebook with someone others subscribe to?

[J]

I've noticed on Facebook, there are those who only have the "SUBSCRIBE" option. (usually celebrities) However, I've seen people who are friends with them, so my question is, how can they be friends on FB if their only option is to subscribe to them?

[TwilightFreak]

If there isnt a add as friend button, you cant. Sorry
But when you subscribe, you will get their updates in your news feed
without actually being friends with them

[Daniel]

Because They Probably have them as a Friend Before the Friend Request Option was Turned Off yes its Possible But Only if they Have the Friend Request Option Turned on

[JJ]

If you have a Facebook profile, you can always add friends, and you can also enable the "subscribe" button which allows the general public to subscribe to your public updates without your explicit consent. This means they'll see your public updates in their news feed, but you won't see theirs (unless you subscribe back).
Additionally, there is a privacy feature on Facebook that allows you to only accept friend requests from mutual friends, so if you find you get a lot of friend requests from random strangers, this can be a way to cut down on that.

These features are available to anyone, not just celebrities. If you enable subscribers and enable the mutual-friends-only setting, then the result is that the general public will only see a subscribe button.