How does facebook suggestions of a friend work?

[Patrice]

In the upper right corner, I notice when I log in,that this guy I like sister is always coming up as an suggestion to add as a friend,but other people that he has on his list or has recently added does not come up at all, actually it never does or has since I ve been his friend..does facebook automatically pick people for you, or would he have to personally do that?

[♥meg♥]

no....the suggestions are friends of friends...they figure if you know that person you know their friends too.

[Hani :-) ♥]

I'm fresh out. That tool is unpredictable. I've had a particular person appear on there consecutively even if I don't have any mutual friends with him and he lives in a different continent ***FROM me. It's weird D: I don't know how they do it.

***edited XD