Despite this, he reckons their loyalty to the franchise is unwavering.
Call of Duty developer Infinity Ward has suggested that the people most engaged with the franchise aren't really gamers at all, as they don't play any titles that aren't affiliated with the series.
That's according to executive producer Mark Rubin, who told OXM that he didn't expect the imminent arrival of the next-gen consoles to have much of an impact on the make-up of COD's audience.
"Regardless of platform - people's gaming habits aren't going to change just because there's a new platform," he said. "We have an enormous amount of players who are more in the casual game space, but they play a lot.
"It's kind of a weird, ironic thing to say; They aren't hardcore gamers, or even gamers, but they play Call of Duty every night. And those guys are going to continue to play regardless of platform. So I think not only will we continue to engage with that existing player base, but we'll take next gen and see how far we can go with it."
Last week, Call of Duty publisher Activision threw down the gauntlet, warning GTA dev Rockstar that Ghosts would be snatching back all the records GTA V has managed to accrue since it released. By the sounds of things, the franchise's fiercely loyal fanbase will be crucial if it's to succeed.
Call of Duty: Ghosts is set to release on PlayStation 3, Xbox 360, PC and Wii U on November 5, with PlayStation 4 and Xbox One versions being available when the consoles launch.