On other sites I've used (mostly local) - it's a requirement to submit feedback - if you don't, you get a warning, then a ban (a week I think) and then another ban (a week again) and then a permo ban. People don't want their accounts banned because if their iTrader ratings are low, people dont deal with them. The point is to create a community of trusted buyers and sellers. I think 90% of us do it as soon as the item arrives etc.