I was thinking there could be a Wall of Trust or a Feedback Section in the forum.
For business done via the marketplace forum, does it seem like a good idea to have a separate section for feedback threads?
The rules for the section could be something like this:
-Topics are 1 per user, to be started by the user.
-Only posts allowed on these topics are positive/negative feedback about transactions.
That way, if someone wants to see if you are trustworthy, they can go to this topic, and see what other people have said about the guy's trustworthiness.