"Sega did pretty good with advertising"
I disagree. Like some marketting campains in the past, the ad contents were fairly obscure and mostly wacky, not really getting the point (rather, the exciting parts) of the gameplay across. This traces all the way back to art/gameplay of the game, which (time and again, this sort of thing) is too intense to display in public (no casual actors performing motions while smiling, which quickly cut to scenes of men being cut in half). So, they're not showing the details of the "real" visuals, and they're not detailing its relationship with the Wii Remote gameplay. And those DeathWatch ads, beyond the Sportscaster guys it was hard to make out anything.
Actually, ESRB has to take part of the blame, cuz all the neat, graphic stuff was cut from the official public-audience trailers (at least in Amerika). Sega/Platinum went overboard to satisfy the ratings guidelines for game trailers. MadWorld also missed the E3 2008 window, meaning Sega missed an opportunity to interface with retailers earlier on.
Considering the fruits of the marketing campaign, i'd say the money was wasted since I'm under the impression that the enthusiast press did a much better job of selling the game than the ads did.