what/who/ are 'people to subscribe to' on facebook?
and why?

look at this guy for example:
https://www.facebook.com/#!/thisisbainz?sk=wall

from what i can see he's not a famous person, just an 18 year old roofer from wales. why does he have 35,402 subscribers?
and what si the difference between being a 'subscriber' and a 'friend'?

here is another one
https://www.facebook.com/#!/scooterbraun?sk=wall

i don't get it.