As you can see, I've already updated the charts according to the VG Chartz numbers recently published.
Xbox One has just surpassed PS4 (in USA) in the 4th week. I see no other reason for this greater pace of the XOne but the stock issues of both consoles that might be affecting more the PS4. After all, within 4 weeks nothing has changed (no new announcements about games, accessories or console features). Or were the PS4 sales more front-loaded due to greater hype? What do you think?
Prediction made in 14/01/2014 for 31/12/2020: PS4: 100M XOne: 70M WiiU: 25M
Prediction made in 01/04/2016 for 31/12/2020: PS4: 100M XOne: 50M WiiU: 18M
Prediction made in 15/04/2017 for 31/12/2020: PS4: 90M XOne: 40M WiiU: 15M Switch: 20M
Prediction made in 24/03/2018 for 31/12/2020: PS4: 110M XOne: 50M WiiU: 14M Switch: 65M
