We reported back in October that the World of Warcraft subscriber base was sitting at 7.4 million, but with the arrival of the Warlords of Draenor expansion last week that number has surpassed 10 million.

It's a familiar pattern with expansion releases: indeed, the same thing happened when Mists of Pandaria released, pointing to the logic behind Blizzard's desire to annualise expansion roll-outs. Still, the pattern indicates that World of Warcraft isn't going away any time soon. The expansion pack itself has sold a whooping 3.3 million copies already.

While the numbers are impressive, the Warlords of Draenor expansion was beset with launch difficulties fairly uncommon to Blizzard. Widespread problems accessing overcrowded servers has prompted the studio to reward players with five days of free access.

We published our Warlords of Draenor review in progress last week, with a final verdict arriving soon. I spoke to designer Ion Hazzikostas last month to coincide with the MMO's tenth anniversary. He thinks the game has another ten years in it.