Concerns from Gamestop shareholders caused the gaming retailer’s stock to fall 19 percent after a story detailing the profit sharing system for used game sales broke on Friday.

According to a report from MCV, Microsoft may work with certain sanctioned retailers that would resell used Xbox One games, with a somewhat eyebrow raising policy that would essentially mean both Microsoft and the publisher would get a percentage of every sale.

Given that Gamestop has enjoyed a 100 percent profit margin on used games since time immemorial, a move like this from Microsoft would be a big deal. In any case, though, they need to figure out their used game strategy before a lack of transparency echoes into a full-scale quagmire.

Via Joystiq