@Demotruk
It's an approximation of course. But some approximations match reality for 30%, others match reality for 90%.
As soon as you admit there are the fans that must have all good first party Nintendo titles, bang... that's your 5-8M group.
All the other intermediate groups you mentioned exist of course, but their existence only _diminishes even more_ the number of hardcore games that are falling in the hands of the really casual Wii owners. And if you start with 5-8M core, you haven't many hardcore games left to start with, except for Mario Kart.
So your intermediate groups will be "hardcore gamers" with different buying pattern than the "core Nintendo fans". They might love Madworld or no More Heroes or Deadly Creatures or JRPGS, but all the numbers for these games are well within the 3M variability we are assuming for the "Nintendo core", so the numerical conclusions still don't change.
