The biggest and only Call of Duty event is beginning tomorrow. Presumably most of the attendees venturing out to Los Angeles for Call of Duty XP will have played Treyarch’s latest addition to the franchise: Black Ops. Because numbers tend to tell the truth, Activision threw out a big one this morning during a analyst call. 23 million people bought Black Ops over the Xbox 360 and PlayStation 3. 18 million of them liked the multiplayer so much–or hated the on-disc maps enough–to buy one of the $15 map packs released for the game. If you want more numbers, that’s about $270 million in gross earnings.

While on the call Activision Publishing CEO Eric Hirshberg noted that they expect a “20 percent-plus” growth in the console install base with the release of Modern Warfare 3 this November.

Via: Joystiq