- Require people to make a single thread and call it their shop. Allow them to make only one and update it according to their tastes. If people post random sell/buy threads give them a warning and so on depending on how many times they do it.
- Allow them to enter a description of their shop so that people can see it. If you could make it that a text bubble would come up when you mouse over the name of the shop then that would be awesome.
Well its a pretty rough idea but it could help stop a flood of spam and a moderating nightmare in the longrun, I welcome your input on developing this idea...