"We appreciate all the enthusiasm that players around the world have shown for StarCraft II," said Blizzard CEO Mike Morhaime. "It was important to us to deliver an overall gameplay experience that was accessible, balanced, and fun, and it's been gratifying to see how strongly the global community has already embraced the game."

Half of the three million sales were made in StarCraft II's first 48 hours of sale alone, which Blizzard says set "the record for fastest-selling strategy game of all time."

StarCraft II: Wings of Liberty was released for PC and Mac on July 27. The other two instalments of Blizzard's StarCraft II trilogy, the Zerg-focused 'Heart of the Swarm' and Protoss-centric 'Legacy of the Void,' will follow further down the line.