[drsintoma]

Well, it takes 2 users to make 1 friendship, so it would be half of that. Plus that's the number of daily users, the total number of users is like double. So the average friends per user must be around 65.

[simondlr]

The average is 190.

http://arxiv.org/pdf/1111.4503v1.pdf

[usaar333]

Huh?

There's 125 billion friendships and 900 million monthly active.

125 billion / 900 million = 139 friendship pairs / user

A pair = 2 friends so you double it to get 278 friends/users.

This is of course an overestimate as people are friends with people who use fb < once a month. Not sure what total user count is though.