Rath on 11 October 2009
I think it is brand recognition more than word of mouth. Mario is one of the most (if not the most) recognisable characters in the world. Just having the words 'Super Mario' in the title is essentially enough to guarantee several million in sales.
Add to that the more core crowd who picked it up because it was so damned good and you end up with the sales that it had.
Of course it will be beaten to a pulp by NSMBWii...
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