I'm deeply skeptical about the claim that "good legs = casual". It's true that games with mostly hardcore appeal generally have huge opening weeks and short legs, but there are too many other factors involved to make a simplification like that.
The Wii, for example, has the quickest expanding user base in the history of gaming, but library of games is still suffering from how the third parties initially underestimated it, and first party resources are limited. New Wii owners are thus buying more "old" games than 360/PS3 owners, and giving lots of games the kinds of legs they wouldn't otherwise have any chance of achieving.
I do appreciate the leg-calculations you've done, though. Thanks a bunch.







