Technically, that's a slight exaggeration, but from the perspective of most other development teams, the sheer number of bodies Activision assigns to making Call of Duty games still boggles the mind.
According to Activision's executive vice president for studios Dave Stohl, the publisher has at any one time around 500 people working on the Call of Duty series. That's more men and women than most companies even have, let alone have to devote to a single franchise.
About the only comparable franchise I can think of is Assassin's Creed, which last I heard could have 400+ developers working on it, and for much the same reason (when you've got to get one game a year on the shelf, you need to be working on more than one at a time).
Call of Duty consumes the time of four or five Activision studios [Gamesbeat]
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