Developers have long complained about piracy's impact on their business model, but it looks like used-game sales could be an even bigger problem. According to Fable III designer Mike West, the sale of second-hand games costs the developer more than piracy. West seems resigned to the fact that piracy will always be an issue, suggesting that games will always be cracked no matter what anti-piracy measures they include. He also laments the fact that "people don't think it's worth spending money on computer games."
If used-game sales are indeed a growing problem, then people do think it's worth spending money on computer games—they'll just spend less if given the opportunity. Thanks to major retailers that seem to be putting an even greater emphasis on flipping pre-owned games, consumers now have a vast selection of used titles from which to choose. Games aren't tangible goods that can wear with age, so you're getting pretty much the same experience buying used versus new. The only difference is that the developer doesn't see a dime when a game is sold second-hand.
Folks should be free to sell the games they've bought, but there's something unseemly about big-name retailers providing a marketplace for those transactions without cutting developers in on the action. Some developers have already begun to adapt by making second-hand buyers shell out for their own multiplayer keys, and I suspect we'll see additional measures incorporated into future releases. Let's hope those measures are less annoying than the DRM schemes ultimately rendered impotent by crackers.