http://www.facebook.com/press/info.php?timeline
2004 1mil in the first year with no funding... pure organic/word of mouth...
2005 5.5mil $12.7 million in venture capital from Accel Partners
2006 12mil $27.5 million from Greylock Partners, Meritech Capital Partners and others THIS IS THE YEAR THEY OPENED UP REGS
2007 They explode the same time MySpace becomes a pile of shit further feeding the flames
The rest is history, tons of press, tons of capital...
You can't be an early adopter if you don't gain traction I guess I should have said that in my previous post... but here you have the first popular (at all) college site... explodes almost off the bat based on word of mouth... there was a DEFINITE need there.
From there they picked up capital and I'm sure whatever investor was dumping cash in put someone in charge that knew what they were doing ;)