Valve's Doug Lombardi has told Destructoid that the best way to combat used game sales and piracy, is to make good games and offer continued support.
"We always see these overall numbers, like how much money GameStop's making per year off of used game sales, but we really don't have a breakdown of details for those," he told the site. "I don't personally know, after being at Valve since Half-Life 1, how many copies of our games per year are sold used, and on the PC versus the 360, so I think there's a certain amount of information that's missing, sort of like piracy. I think a lot of folks cry piracy when a game fails to hit their forecast and it may or may not be part of the problem, and it may or may not be all of the problem, but I think to throw any one reason at any problem is probably a mistake, considering the lack of information on both fronts.
"Having said all that, though, I think that it's probably true to say that gamers tend to have affinity for the games that they like, so if you're doing your job and making a good game, and providing a high level of service for that game at the time of release and post-release, I'm guessing you're probably less of a victim of piracy and trade, because people want to have the full copy, the legal copy, and have all the updates.
"I think there are ways of curbing both piracy and used game sales by providing a higher level of service at the time of launch and post-launch. And I think what we're seeing, as platforms become more and more connected, that this problem will become less and less an issue as the idea of offering a service post-launch becomes more and more en vogue."
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