I have two hard copy JP 3DS games and over 30 digital titles. And my Dad is bigger than your Dad.It'll be hard to calculate considering a lot of people download their games from PSN with their Vitas. I have 1 hard copy game and 10 digitally downloaded titles.
Edit: my point being that one cannot definitively use digital hypotheticals for sales data unless such data is released. And there's probably a good reason when data is released and good reasons when it all too often isn't.