I would beg to differ. I would see no difference in leaving bad feedback (as ebay users do) or bad comments (such as the better business bureau does) on a separate thread. This allows the other party to rebutt the comments (or embarass them into doing the right thing). The group we have here, I don't see it happening, where we would have to resort to this sort of thing. However, there is a vast cross section of people on the "other" sites that do have a problem.
An example is my wife ordered a part on ebay. Paid in advance. It took a month to receive from Florida. It was the wrong part. Contacted seller, he acknowledged it was the wrong part and asked us to ship it back (at our expense even though it was their fault). Wait a month, no part. Filed a complaint with ebay and the Better Business Bureau. Seller claims he never received the part.
Fortunately, we shipped it UPS. Contact ebay and seller that the part was delivered and signed for 3 weeks earlier. Seller then agreed to ship part. Wrong part arrived again. E-mailed seller, no answer. Left complaint in the system to warn other buyers of seller. So all in all, I think 3 months was patient enough....Live n' Learn