The milestone comes roughly a month and a half after Blizzard announced the November 13 release of Wrath of the Lich King--the title's second expansion pack--and noted that the game had more than 10.9 million subscribers.

"It's been very rewarding to see gamers around the world continue to show such strong support for World of Warcraft," said Blizzard CEO Mike Morhaime. "We remain fully committed to responding to that enthusiasm with a high-quality, constantly evolving game experience."

Although Blizzard has another MMO in development, the studio recently promised that the new title will be "different" and vowed that World of Warcraft will be supported "as long as people want us to support it." WoW is expected to net at least another 1 million subscribers across the next year, according to analyst predictions.

World of Warcraft's Subscriber Definition
World of Warcraft subscribers include individuals who have paid a subscription fee or have an active prepaid card to play World of Warcraft, as well as those who have purchased the game and are within their free month of access. Internet Game Room players who have accessed the game over the last thirty days are also counted as subscribers. The above definition excludes all players under free promotional subscriptions, expired or cancelled subscriptions, and expired prepaid cards. Subscribers in licensees' territories are defined along the same rules.