goozex.eu are offering one free used game when you sign up to their website. The website allows you to trade your unwanted video games with other users and implements a points system as currency. You send a game to someone and earn points which can then be spent on a game for yourself.
If you sign up to Goozex you will receive 100 free points. This is enough for a fairly old game but if you can think of a game you wanted to get a couple of years ago then you have nothing to lose. You can request games from all current game systems.
Sorry if I haven't explained it that well but all the details are on the website!
When you sign up you will be asked for a coupon code.
You will get an extra 100 points after your first successful trade which you can use to get an extra game! I don't know whether spending the first free 100 points is classed as a trade or not but potentially you could get an extra free game!
Hope this was helpful. Hope I get my free game! Oh and also you don't have to enter your card details, just your address )