Crazzy, stop a second and read the posts again, I feel some of the other people have to repeat themselves several times to try to make you understand.
@Valen
By 30 % he meant that there are 6.5M mario fans out there, and that they have bought the Wii, and that there aren't many left.
But seriosly, you have to remember that some people buy many games, other buy few. Take a scenario here:
Person 1: Buys 3 games to his Wii each year. Let us say that normally this would be Mario Galaxy+ Mario Kart + Brawl. However, this guy might instead buy Mario Galaxy + Mario Party + Mario and Sonic. However, the person rarely changes out the Mario platformer.
Person 2: Buys 6 games a year. Let's say SMG+MK+SSBB+No more Heroes+ Twilight Princess. If he is more of the party game guy, he would still buy SMG. Just change out NMH and TP.
Ok, that was not very good, but another way then.
Most casuals would buy SSBB, MK and SMG.
Most hardcore would buy SSBB, MK and SMG.
You see, I have never liked Mario Platformers (SM64 and SMS are the only that came out in my time, and I didn't like them), yet I bought SMG, because it is the Mario Platformer. Think of it, it is the top of Nintendo's top. Nintendo IS Mario (and SSBB, Kirby, Link, and so on, but you get my point) they are 11 million sellers made by Nintendo on Wii. 5 of them are Mario, and the platformer is the best Mario. Really, I would say that 13M at least, of the people who bought GCN are "Marioboys"
A football (Soccer, for morons) game sold 570K in USA, because it is Mario!
Mario is the video-game icon, and this is his best, who wouldn't buy it?
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS