Do special editions count as three sales or two sales or one sales, and how does does downloading dlc count into this.
Awakening is close to 2 million now according to the Japanese singers bio.
I suspect it means total physical+digital copies of any base product, either Birthright, Conquest or the special edition, with a SE sale counting as one. I doubt the SE counts as more than one, and I doubt any downloaded additional campaigns count either (So if you bought a boxed Birthright, and then Conquest as DLC, it's still one sale). A DLC campaign might be a sizable expansion, but it's still a piece of DLC to a base product, no matter which way around you do it.
Aside from numbers of copies, and more importantly for Intelligent Systems, total profits from the project will probably be very high compared to Awakening too, seeing as there are potentially multiple £20 items of DLC on top of the smaller pieces. It'll be interesting to see if they eventually release numbers of how many DLC campaigns were downloaded, and how many chose either Birthright or Conquest as their initial standard edition.
Madness that it's now a major B-tier IP for them, considering it's genre and lengthy history as a minor footnote in their catalogue.