Well, we have to remember that on Black Friday weekend, HALF of all the games sales were digital. So I would say it's probably at least 30% which would put it at 4.5 million.
I know many users and all the retailers do not like me saying this, but I see no reason to buy physical (unless it's a fetish or you are a collector or slow internet/caps). PC games sales are nearly all digital, why should the consoles hold back.
Especially they way you can quickly switch between games on the Xbox One, it makes more of an incentive to buy digitally. And people do, even if it's a little bit more expensive.
So I think Halo V will continue to grow. I haven't even bought it yet (A great deal for The Witcher 3 came up first) And I think it will have great legs - but most of those legs will be digital.







