Blizzard made the announcement just weeks before the November 13 launch of the highly-anticipated expansion, Wrath of the Lich King. One analyst estimates that the expansion could boost the subscription base another 1 million players over the next 12 months.
In a statement, Blizzard CEO Mike Morhaime said, "We remain fully committed to responding to that enthusiasm with a high-quality, constantly evolving game experience."
In late July this year, Blizzard said the subscription base for WoW had hit 10.9 million.
WoW originally launched in 2004.
In China, many gamers play WoW at Internet cafes, gaining access to accounts by purchasing CD keys as opposed to monthly paid subscriptions. U.S. users pay a monthly subscription of $13-$15 per month depending on the payment plan.
The first expansion, The Burning Crusade, released in 2007, selling 2.4 million copies in its first 24 hours.