Escrow , the most important thing that can help you from scammer members, if me i never respond some offers that people i don't know try to offer me 
Escrow can be a help or a disaster too the first thing i have learned during transacting online is that there is no such thing that guarante safe. Even using escrow is not safe because when the time comes in need where money can blind a person's humanity there comes a disaster to people trust him.