As an addendum to the argument I just made, I'd like to strongly encourage every sales age poster to begin speaking in demographic terminology rather than in internet jargon like "casual" and "core". If someone were to check my post history, you'd likely notice that I nearly always put the word "core" in quotations, because I strongly dislike it. The only advantage to such lingo is that it is shorter to type.
On the other hand, I think there is more substantial evidence to support the demographic discussion (for example, games like Mass Effect, Bioshock and Call of Duty did very well on the 360, but so did Madden and Fifa, neither of which I think of as "core," but which I do think lean heavily towards the 16-30 year old male demographic that enjoys games like Bioshock). In addition, these definitions are much clearer: saying 16-30 year old males instead of "core" will prevent discussions like this one from breaking down in to arguments about what "core" and "casual" mean. My definition brooks no such opportunities. Lastly, I believe demographic terminology, by the very nature of its empiricism, removes much of the stigma that has come to surround both the word "core" and "casual." It has become too common to mock the "casuals" for their pedestrian taste or the "core" for their stubborn myopia; I believe such vituperative discussions would become less frequent if people were forced to talk about, say, 16-30 year old women in a direct fashion, rather than smearing them with the maleficent and nebulous term "casual."
I believe we will find that such diction minimizes vagueries and focuses discussion on more tangible argumentation.