Re: But hang on..
You seem to forget that early in the RRoD days many, many consoles were replaced at the point of sale. Therefore, for someone who suffered the failure, their single purchase was recorded as two shipments to retail. The figures discussed here are shipments to retail.
Lots of gaming/tech journalists/analysts have tried to guess the retail-replaced figure, and none I've seen suggest it's lower than a million. Of course, MS could clear it all up now and tell us the figure, but they have never even been prepared to deal with the question (that tells you it ain't pretty). I remember Aaron Greenberg being asked for the figure in a video interview in the States, and he just blanked the journalist and silently waited for the next question.