Competition for Facebook

Did you notice all those niche social networking sites cropping up all over the place?

Basebook for ballgame enthusiasts.
Bracebook for dentists.
Casebook for serial killers.
Chasebook for GTA players.
Dazebook for dreamboats.
Faithbook for fundies.
Glacebook for cooks.
Grazebook for cows.
Hazebook for bullies.
Lacebook for steam punks.
Lazebook for Dudeists.
Macebook for feminists.
Pacebook for runners.
Phasebook for trekkies.
Racebook for white supremacists.
Tasebook for pigs.
Tracebook for hunters.