... a measure of the value and effectiveness of online auction sales. I would rank it well below good product, fair price and good service (that is, prompt delivery, good packaging, etc.).

As I said in my response to Tokeneer, no other retail venue relies on "feedback" as a measure of how good a buyer or seller is. If there was no feedback system, a brief email ("your check arrived") would acknowledge receipt of payment as easily and as effectively as feedback. Ditto delivery of the product ("my item arrived safely").

You may be right that the eBay feedback system is a relatively convenient way to accomplish these acknowledgements -- however, that is neither the primary purpose nor the primary use of the feedback system. You'll notice, however, that neither of the messages suggested above requires a Ph.D. either. ----- jim o\-S