They could put a fee on it, just like they do for cards and in-game items, then share with the publishers/developers.
Sell a game for $10, you take $9, valve take $0.50 and gives $0.50 to the publishers.
I see this working well for games that are no longer available to buy on the "new games" store. For example, the Deadpool game, It's no longer for sale, but I have a copy the I son't play anymore. I could sell it for a few bucks for someone who wants it.
Sell a game for $10, you take $9, valve take $0.50 and gives $0.50 to the publishers.
I see this working well for games that are no longer available to buy on the "new games" store. For example, the Deadpool game, It's no longer for sale, but I have a copy the I son't play anymore. I could sell it for a few bucks for someone who wants it.