I have been trading video games and movies online for 13 years now and have done over 500 trades on other sites. They all go by the simple rule of lower feedback sends first. Or you can send same time with users with similar feedback. I have seen so many people here just send payment right away to new users with 0 feedback. You guys are way to trusting and really should start looking at who has more/similar feedback before just sending money to a stranger. That hardly ever goes well. I am more than happy to send payment first to someone with higher feedback or someone I have delt with before. But I will never send payment before getting codes from a new user or someone with less feedback than me. Be glad you guys are only getting ripped off of a few bucks for codes.
I have seen people on my other sites ripped off for stuff like video games/game systems/loans.