Truth be told 75M was actually leaked to someone I know on here who told me about it then, which is funny that I had information millions did not.
Also, according to this source I know, Brawl's advertising budget was about a $1 million, and Smash For the 3DS and Wii U is "22.5 million dollars", most of it aimed for Smash Wii U.
Also, Melee's roster leaked a bit early as well, Ultimate Marvel vs. Capcom 3's roster leaked early (the same guy who confirmed the 4 character E3 thing is the guy who leaked that on GameFAQs), etc.
Alas, leaks are inevitable.
...ummm... leaks draw attention to a game, thus they are in a sense more likely to be good than not good, especially if the game is of a high quality.