Sales figures in general weren't quite as spot on as they are today. Toy Retail Sales tracking managed most of it for the United States and were not the most accurate as their numbers came from a small number of high volume retailers and they averaged those figures based on market share estimates to fill in the blanks.
NEC/TTI definitely knew how many units were manufactured and shipped to retail. But sell-through to consumers was a lot harder to track. I recall hearing stories from TZD about the sheer mass of inventory they got back from Toys R us while TTI was shutting down.
I suspect there were probably 3 times as many TurboGrafx CD systems and Duos sold in the US as there were copies of Cosmic Fantasy 2 sold (meaning my guess is around 60,000). We could throw LaserActive TurboGrafx PAC numbers on there, but it wouldn't increase the number by much if at all. I think the Duo sold quite a bit better than the CD attachment, though still not well enough to be considered more than a niche in North America.
Funny you say this, in the podcast, he states that the DUO didn't add to the user base much at all. (barely, in his words)
He also makes an estimate that Sega CD was roughly 3X the install base at 60K.
Again, just Vic being Vic
It all plays into his cospiracy of "the only thing that ever held me back was outside forces!", which continued to haunt him as he jumped from console to console.
This.
But he does mention that WD was responsible for making Sony change the rules in regards to some areas of packaging. Specifically, he says that Sony used to publish all the manuals themselves (for PS2) and had to be provided the content in order for the manuals to be made. WD came in and fought this so they could produce higher quality manuals.
