I have been reading and learning a lot these days about marketing. I heard a term for something called "Social Proof" and it put some stuff in perspective for me.
Basically the concept of social proof is a psycological concept that people like to belong with others and do what other people do vs. being the first to try something. Why are sites like ePinions and reviews on Amazon so important? The provide "social proof" that something is good.
This is a very important concept if you are trying to launch a new product in fact there's a good series of articles by Yaro Starak that talk about this and more.