And Mass Effect 2, BioWare's sequel to the 2007 action role-playing game, sold 572,100 copies for the Xbox 360 with just six days in stores. That makes Mass Effect 2 the best-selling game to ever be released in January, says Jesse Divnich, analyst with EEDAR (Electronic Entertainment Design and Research). "By a huge margin," he says. "Typically, January is reserved for holiday season overflow and people who didn't buy games like Call of Duty over the holidays. Publishers are always afraid to introduce triple AAA titles in that month."