what about offline events? Are they effective? I recall Yelp did a lot of that in the early days.
According to pud, it depends. He gave Evite as an example, but mentioned that Yelp did something similar.
MySpace also had a pretty good viral loop that went like this: 1) See small thumbnail image of Tila Tequila's boobs 2) Click image to see larger version, then forced to create account 3) Create account, use contact importer, email everyone you know
I think they didn't start throwing events until they were big.