A week or so ago, Gamestop introduced a promotional campaign that would allow PowerUp members to upgrade certain Xbox 360 titles to their Xbox One equivalents for only $9.99. Well, Amazon must've thought that was a pretty good idea, because it just unveiled a trade-in offer of its own. The promotion only applies to certain titles such as Call of Duty: Ghosts, Assassin's Creed 4: Black Fl
