Gavin knows how to do viral marketing well. I'm writing this, arn't I? :)
[Update]
Here's another great viral marketer:
“Anyway, John offers an interesting deal on his website. He writes:
Imagine you are applying for a job and the interviewer asks you this question. How would you handle it? Send me your most creative answer to jkador@jkador.com and I’ll use your answer with credit to you in the book. I will also send you a signed copy. This is not a trick question. Any prisoner in the country can try it.
You are a prisoner in solitary confinement serving a life sentence. It is Friday afternoon and you absolutely must have a cigarette. The only person who can give you one is the guard outside your cell. What do you do to get a cigarette? “
(via Gretchen)