Generally speaking, the videogame industry sees the sale of games come primarily at launch before quickly tapering out. Nintendo games and Call of Duty games are some of the few exceptions to this. Whereas even many big titles will disappear from the NPD sales charts within a few months of launch, the latest Call of Duty traditionally has a long stay at the top before sticking around in the top ten long after when the majority of games would have fallen off. Modern Warfare 3 has yet to drop out of the top ten but it is doing more poorly than Black Ops was at the same point last year, leading some to wonder if the Call of Duty bubble is ready to burst. The series' haters may want to delay celebrating just yet, however, as it's hardly as if Activision is on the verge of being forced to shelve the series like it did Guitar Hero last year.