> Go to club with a big group of friends.
> Mix group of friends with several other groups of friends.
> Big group photo shoot.
> Pictures gets uploaded onto Facebook, and the individuals are tagged.
> Individuals add other individuals in the pictures.
> Rinse and repeat.
I think that's how it works. A lot of my friends who have > 1,000 friends are really social, outwards 'party-animals'. Those with > 2,000 are Internet famous: popular blog, YouTube famous, or notorious musician on the Internet. Also works better with clubs like LGC (I think it's LGC, I can't quite remember the watermark), where they take the pictures and upload it onto their Facebook page.