Originally Posted by Brother None 
Yeah.
IGN mentions that skews the numbers, and it does. But do you think purchasing through downloads is really so big now that it'd significantly alter the numbers? I have my doubts.
I don't know, but in The Witcher discussions here and there I frequently see people mentioning they bought the downloadable version. This is the feeling I get, no hard numbers of course

But I thought e.g. Steam was a player sufficiently big that its exclusion from NPD reports would be worth mentioning.