riecsou on 25 January 2015
So we have those numbers from VGChartz:
Week Ending December 6th PS4 648,059 3DS 503,311
Week ending December 13th PS4 681,241 3DS 576,678
Week ending December 20th PS4 717,582 3DS 744,657
Week ending December 27th PS4 736,812 3DS 724,174
Week ending January 3rd: PS4 420,708 3DS 412,496
Total for month of December including January 1st to 3rd: PS4 3,204,402 3DS 2,961,316
We can assume that the tracking for the PS4 is close since the numbers are really close to the numbers we got from Sony.
So the 3DS would have to be undertracked by around 250K for it to have beaten the PS4 in December.
