The PlayStation 4 is difficult to find in stores because consumers are snapping it up at a fiery pace.
Sony revealed today that it has sold more than 4.2 million PlayStation 4s by Dec. 28. That doubles its previous sales figures of 2.1 million on Dec. 1. Those numbers both represent the system's worldwide performance.
For comparison, Microsoft announced yesterday that it sold more than 3 million Xbox Ones worldwide by the end of 2013.