"They went on sale in GameStop yesterday; these things started to fly off the shelves," senior vice president of merchandising Bob Puzon toldGameSpot. "It's a huge win and a huge opportunity for us."
Puzon also noted that the original $499 Xbox One is still "very vibrant" for the retailer.
Microsoft reported in late April that Xbox One shipments totalled five million units. PS4 sales stood at seven million units as of April 6, according to Sony, with both platforms having launched in November 2013.
Microsoft made a number of significant announcements in the run-up to E3. Aside from the Kinect-free Xbox One, Games with Gold launched on the system, while entertainment apps are no longer locked behind an Xbox Live Gold subscription..
The announcements cleared the way for the company to focus on game-related reveals during its E3 press conference on Monday.