America is the biggest market for Smash Brothers, bar none. That's indisputable now. If you look at the Japanese and then look at sales of Wii games, especially in comparison to American sales, everything becomes clear. A great example is Mario Galaxy, which got the reception it deserved, sales-wise, in America, but remains not even in the top ten in Japan in favor of games like what, Mario and Sonic at the Olympics? With Nintendo games, it just seems like the Japanese haven't been buying up the heavy-hitters as much as Americans. In fact, I'm pretty sure Zelda, Mario, and Metroid have all sold better in America (but you can correct me if I'm wrong). At this point it's easier to think Smash will see more success in America than anywhere else because of it being the last of the heavy-hitters, thus a potential reason arises to please American gamers.