I had the impression that this game was selling very poorly, but it seems that I've been proven wrong. I'm quite surprised that a game that appeals to mostly younger audiences has been able to stand out this amount of time, and on a system with an older, more teenage audience as well. Based on the American sales charts, it may even surpass your prediction of 25k-50k copies during the holidays. The game has been able to maintain steady sales over time, being able to last until the beginning of August, when it stopped being tracked. With the nearing holiday season, I'm sure the boost and higher userbase can push at least 70k copies in the Americas alone. The PAL regions also appear to be interested in this game moreso than the others. It most likely will hit a million in its lifetime.
