  For product rating environments, similar to that of Amazon Reviews, it has
been shown that the truthful elicitation of feedback is possible through
mechanisms which pay buyer reports contingent on the reports of other buyers.
We study whether similar mechanisms can be designed for reputation mechanisms
at online auction sites where the buyers' experiences are partially determined
by a strategic seller. We show that this is impossible for the basic setting.
However, introducing a small prior belief that the seller is a cooperative
commitment player leads to a payment scheme with a truthful perfect Bayesian
equilibrium.
