Sorry if this has been mentioned before, but I think I could help to have a set of rules in the marketplace forum, for example:
Do not just post: "I have an ______ does anyone want to trade for it?".
Instead, post a list of what you are interested in trading for/how much you would be willing to sell it for/etc.
Do not start a waiting list or creating a thread asking if anyone would be interested in buying something unless you have already created a puzzle and have pictures or a video posted.
My thought is that if anyone was to break these rules, their thread would be deleted, and if it continued further measures would be taken.
Does anyone else have any feelings about a set of rules for marketplace, or does anyone else have suggestions for rules?
Also, this thread is not directed at anyone in particular, it's everybody in general.