I don't like to disagree with anyone but I do think there are instances where feedback is important for buyers.
1)Quite a lot of sellers won't accept bids from people with no or low feedback. I was looking at an auction today which won't accept buyers with less than 10 positive feedback.
2)If you want to become a seller, it's a good idea to have some positive feedback as a buyer under your belt first. That way people (like me nowadays!) who have doubts about zero-feedback sellers don't feel they are taking a big risk - they can see that the seller has proved him or herself reliable as a buyer.
I've been lucky enough to only have one or two sellers forget to leave me feedback. Once I venture into selling myself, I expect things will get more complicated!
SuperSqueaky