Dunbar’s number says we can only sustain 100-230 friends. 

It holds up online too; despite how many “friends” you have you’re probably only active with about 100-200 of them consistently. Facebook promotes mainly weak, low-commitment friendships anyway. And the main reason for un-friending is because somebody posts too much uninteresting crap.

Your Facebook profile probably reveals your true personality. 

It’s especially indicative of how extroverted and open to new experience you are but it can also tell people whether you haveanxiety and even predict your job performance.