pcstation4 on 17 January 2017
Nobody really knows. If it gets the best Japan support any console or handheld has ever seen it may come close to 20 mil. I don't see it selling over 20 mil. Handhelds are declining in Japan, so unless Nintendo can some how get all of those mobile games that are so popular in Japan onto Switch, It will most likely struggle more than the WiiU.
It's funny that after PS4 success, people still think a console can depend so much on one region. Japan won't save Switch just like US won't save Xbox.
