I think the fact that wii u is underpower compared to other consoles on the gen is a reason why 3rd party games don't sell well on wii u and lack of 3rd party support mean the console will fail
PS4 - over 100 millions let's say 120m
Xbox One - 70m
Wii U - 25m
Vita - 15m if it will not get Final Fantasy Kingdoms Heart and Monster Hunter 20m otherwise
3DS - 80m







