Proudly display mine. I think it gives you some insight into what a persons tastes are. Pretty harmless in my opinion.
I don't often get messages looking to sell, but in the past, it has led to pleasant, easy sales. I have not had it used against me for insults, but I am not mucking it up often enough to make people have reason to, generally.
I find it flattering when someone asks to sell, and "no" is pretty quick and easy to respond with if I don't have the desire.