Gamestop's whole business was used games. I mean they'd sell you a new copy happily, and you could sell it back at discount and spend the money on a different used game

Playstation / Xbox digital stores killed the market, now I pay $60 for the new assassin's creed and can never sell it, there's no such thing as a used game anymore

If Gamestop has streaming rights for certain games, then NFTs can represent who ones a copy of a game. If you're bored of a game, sell the license to play to someone else. (This is not even mentioning in-game items that could be traded on secondary markets)

Of course GameStop could conceivably build a tech stack that lets them manage 'who owns what license to what game' and a whole marketplace around that, but why build it yourself when people are already out there sending NFTs from one wallet to another.