Activision Blizzard has announced that World of Warcraft: Cataclysm, the third expansion for the most popular subscription-based MMORPG available, has become the fastest-selling PC game of all time in terms of first-month sales. Based on internal company records and reports from key distribution partners, the company sold more than 4.7 million copies in its first month of release.

The number of sales isn't that much larger than sales for day-one: 3.3 million copies, which made it the fastest-selling PC game in terms of first-day sales. World of Warcraft: Cataclysm was simultaneously released in the US, Canada, Mexico, Argentina, Chile, Europe, Russia, Southeast Asia, Australia, and New Zealand on December 7. It became available in Korea and the regions of Taiwan, Hong Kong, and Macau on December 9.

"We created thousands of new quests, introduced new lands to explore, and extensively revamped the game world for World of Warcraft: Cataclysm, making it our biggest and most ambitious expansion yet," Mike Morhaime, CEO and cofounder of Blizzard Entertainment, said in a statement. "We've been floored by the community's response so far, and we'd like to thank them for their continued passion and support for World of Warcraft, and for helping Cataclysm reach this incredible milestone."