Why not allow the community to "refund" (for lack of a better word) games they no longer wish to play for steam cash.
I say similar to the cards because there is a market where you sell them, yada yada, you all know. Why not do this but with games..? Allow us to have our own economy in a way maybe, the topic is out there, and is yours to do with as you wish.
PLEASE, make this viral, talk about it, spread the word like it's your gf's legs. Lets get some sort of thing going where its not really a lost cause to buy a game because there is always in store credit. Game stop does this and they have so much business because of store credit.