Activision said that latest release Modern Warfare 3 had 20 million users per month and Black Ops had 10 million, according to VG247.
Modern Warfare 2, which was released in 2009, still saw five million monthly users, with the remaining numbers spread across earlier titles.
Social network Call of Duty Elite has seen seven million registered users since Modern Warfare 3's November release, with a total of 1.5 million paying subscribers.
Meanwhile, a Modern Warfare 3 Content Collection will package downloadable content into a retail bundle on Xbox 360 this March.
Activision's revenues for 2011 were at $4.76 billion (£3 billion), compared with $4.45 billion (£2.8 billion) year-over-year, with digital and online revenue doubling to $1.5 billion (£947 million).
The publisher teased that this year's Call of Duty release will offer "meaningful innovations".
Watch a trailer for Call of Duty Elite map packs below: