So on the back of the recent EU ruling here we have Gamestop first to stick their heads above the parapet.
Source http://www.escapistmagazine.com/news/view/118762-GameStop-Wants-to-Sell-Used-Digital-Games
The world's largest gaming retailer is researching "technologies" to create a secondhand digital market.
According to GameStop CEO Paul Raines, the retailer is considering "some technologies out there in Europe" that would allow them to create a used games market. Raines didn't elaborate on what these "technologies" were, but noted that "a few companies, a few startups" were already using them.
Source http://www.escapistmagazine.com/news/view/118762-GameStop-Wants-to-Sell-Used-Digital-Games