For some people?
10 billion units at least, or else it's flop city!
In reality, anything... just not to be the whipping boy of the Vita would be a good thing. Just to keep up with the X1 or maybe move up at 3/4 of the PS4 right now, that would be fantastic work and a great comeback for Nintendo from the Wii-U failure.
Why not check me out on youtube and help me on the way to 2k subs over at www.youtube.com/stormcloudlive