Well I guess it makes sense in Japan then. I just see stuff like this as something you would just keep on the system all the time so you don't have to go through the "hassle" of popping in a disc for a couple of minutes of play time. It might not be a huge risk, but I'm sure if they published say 150,000 discs in the US and only sold 5,000 (or anything less than a vast majority) it would upset those who really matter to Nintendo, the fans shareholders.