Well, isn't "traffic comes from lifehack type websites discovering it and linking to it" the equivalent of "dude, you've got to check it out"? True, not everybody does it in your case, but it wasn't YOU the initiator of those links. Its pretty much the same thing concentrated in hands of few individuals.
But it is rare that people spread the word to other people i.e., very little traffic comes from email websites, small blogs, or directly typing in the URL. Instead almost all of the traffic comes from lifehack type websites discovering it and linking to it.
So in my case I don't see the specific p2p type word of mouth he talks about. I think that only applies to certain products where you actually want your friends to use the same product as you e.g., "dude, you've got to get a myspace account".
What do you guys think?