I was planning to setup a marketplace forum, but since then, decided not to. An idea I was contemplating with, was having a middle-man exchange. So, if I wanted to buy forum software off of someone, a moderator would act as the middle person. I would send the money to the moderator, the user would send the license to the moderator whom would verify the authenticity of it and would transfer accordingly. Could be a good idea to stop fraud? I'm in the process of buying a vB license. and would happily pay someone $5 to act as the in-between. Maybe not even a moderator. Maybe someone with a sufficient iTrader score, or a premium account.
What you are talking about is an escrow service. There are many existing escrow services out there already.
This would give Shawn an opportunity to capitalize in the buy&sell section. That is if its worth the effort.
There's far better ways to monetize our Buy/Sell/Trade area if we wanted to. People already can use escrow services and they choose not to. Why would it be any different if we offered an escrow service (which probably would need to be more expensive than normal ones since we wouldn't have the volume they have).
Right... an option of using an escrow service is already available, users just choose not to use them. It would be no different if we offered an escrow service.