If they were offering fair prices for the games you trad ein, like what they sell them for, then this would be a decent deal. But since they only offer you like 12 ~ 14 dollars for a game they are going to turn around and sell for twice that or more, maybe just 5 less than full price, then in the end you are going to turn in a lot of games at a loss to yourself.
I say this deal, if true, is in poor taste and takes advantage of the consumer. That's why I never trade in games, because they just don't offer a fair realistic trade in value.