It's not perceived safety. If a scammer cannot see any posts, they will go somewhere much easier to scam. The general rule to any buyer or seller here is to make sure somebody has some sort of feedback and history on the boards, so somebody with just 1 post would raise red flags anyways, regardless of your integrity. If you don't want to help others with issues, or even socialize a bit, how do you really convince somebody you are a good honest person buying something?
I wish you luck in selling on FM (pay the $75), or ebay (10%+ in fees) or craigslist driving somewhere to meet them and then deal with the lowball offers that invariably follow. Of your options, this is the lowest cost place, and it only requires a little bit of your time to post in various threads and help others, ask questions, etc.
Good points. It costs money to sell elsewhere. And it is no secret that everyone wants something for nothing.
All Pekka has asked us to do is simply give a little bit of our time participating in this community, before capitalizing on the finely focused market created by this community. I think it is a fair trade.