For a limited time (Til Thursday, November 15th to be exact), you may receive an extra 20% off your purchase of a used PlayStation 3 title at GameStop retailers.
Also as something worthy of mention, if you use your EDGE card, which accounts for 10% off of used games, it will be a total of 30% off any used PS3 title! So for those folks out there who have not picked up one of the great PS3 titles lately, now would be the best time to go out and do so. There has been some word that people was lucky enough to buy Call of Duty 4 at a low price because of the 20% off coupon offer in addition to the 10% off by using an GameStop EDGE card.
For those who are wanting to know what is an EDGE card, well that is simply a card that allows you to take 10% off used games/movies as well as an additional 10% credit on trade-ins.
Make sure you go out now before this offer ends on Thursday!
Source: PS3fanboy