Aerys on 16 February 2014
PS4 is not underperforming, second best 1st january in the history, and it's just not in stock (low stock than wii obviously)and not in japan yet, it's doing on par with wii without japan
Predictions for end of 2014 HW sales:
PS4: 17m XB1: 10m WiiU: 10m Vita: 10m