Gamestop has since foxed this, but anyway..

Say you had games you wanted to sell for cash, but hated the fact they offered you pennies. Mind you this was a bit of a process and usually involed 2 trips to gamestop.

I would find a used game that i wanted (used being the key here) then take the games i wanted sell and trade them in on X used game, enjoy the game for a few days, then take it back for a refund as you have 7 days to return a used game. Like magic you got the trade in value back in CASH rather than the measly amount they would offer you if you were just looking to sell the game. Sometimes on newer games, that could be a $15 difference..

Now they give you the cash value back on a gamestop card... Was fun while it lasted.