Next Generation has this piece up with actual sales data for the US market last year (usually you have to pay for this stuff). I'm extremely glad to recieve this data for free, but I have to take task with one of their conclusions:
Any would-be game publishers looking at these stats would come away with one of two strategies. Either, to create an absolutely amazing game on few platforms (Gears; Zelda; Oblivion; New Super Mario; Guitar Hero) or to sign up an animated movie and release it on every platform conceivable.
Well I can't disagree with the second point - if you wanted to create a new profitable publisher, you would be sensible (in commercial terms) to focus on licensed product, because nothing works better in the mass market than a ready-marketed franchise, and since the license is what's selling your game a platform exclusive gets you nothing.
But I can't agree with the former. How exactly can a new publisher hope to produce "an absolutely amazing game", exactly? And of the games cited, only Guitar Hero is the product of anything but giant investment plus established studio/franchise (and I am doubtful anyone could have predicted the success of Guitar Hero, despite its obvious strengths).
A new publisher cannot plan for an absolutely amazing game. An existing publisher cannot easily plan for an absolutely amazing game, for that matter, otherwise we'd be inundated with them. Absolutely amazing games generally happen when absolutely amazing developers get absolutely amazing sums of money, absolutely amazing quantities of marketing support - and either make a sequel to an already successful game, showcase new technology on a virgin platform, or get lucky.
Does anyone think otherwise?