WoW made half of Activision-Blizzard earnings

This does not come as a surprise to me. The popular MMORPG World of Warcraft topped the Activision-Blizzard's money-makers list for fiscal year 2009 racking up about half of its earnings, financial analyst Arvind Bhatia of Stern Agee said. With 11.5 billion subscribers (December last year), it's no wonder that this gold mine outperformed Call of Duty, Guitar Hero and other titles.

...he expects WoW subscriptions amounted to earnings per share of about 30 cents out of a total 60 cents, or around $400 million total, in the fiscal year ended in December.
-Edge-Online

Even with the release of several competing MMORPG titles last year, WoW's growth showed no sign of slowdown. The report mentioned only the income from monthly subscriptions. Taking into account the epic release of Wrath of the Lich King, the actual figure which includes sales from the expansion title may even be higher.