Microsoft and Sony already went head to head with worldwide sales numbers for 2013 and while the PS4 rode is out front there (4.2 million to 3 million), the Xbox One apparently sold more systems in the US last month



From Engadget:

December figures from the NPD group arrived today, and Microsoft is touting 908,000 sales for the XB1 that put it atop the next-gen videogame systems, and 643,000 for the Xbox 360. That puts it third overall on the home hardware list and first for its generation of hardware. Per Joystiq, Sony's response to the data is that the PS4 remains "cumulative leader for next-gen sales" since its launch November 15th, a week ahead of the Xbox One.

  Microsoft: Xbox One is #1 in the US for December with 908,000 consoles sold