Guild Wars II has now sold over 3.5 million copies, developer ArenaNet announced today on the game's first anniversary of release in August 2012.
The game also reached a milestone of over 460,000 peak concurrent users during the year, though it's not clear when this figure was achieved or what player levels are today.
Studio president Mike O'Brien said the fantasy MMO sold "far beyond our expectations" and recalled that sales were at one point shut down to avoid overwhelming the game's servers.
Guild Wars II is the fastest-selling Western MMO ever, according to data from research company DFC Intelligence. The game's playerbase is expected to grow substantially when it is released in China.
O'Brien penned a blog post speaking to achievements made and struggles endured during the year. He said creating Guild Wars II was an "enormous undertaking" of two hundred developers working for five years to bring the game to market.
Now the company's focus is keeping Guild Wars II a vibrant and compelling place to visit.
"The real challenge is in evolving the world over time," O'Brien said. "And I think the real mark of a success of an online world is how that world grows and evolves, and the extent to which players can take the world and make it their own."
O'Brien said he is very proud of the company's ability to release new content for Guild Wars II on a regular basis. In the game's first eight months, ArenaNet shipped eight major releases; and in the following four months, the studio released eight more substantial releases, he said.
"We're releasing new content every two weeks. Think about the power of that," O'Brien said. "We're now updating Guild Wars II about five times as often as the typical MMO."
Check out O'Brien's full blog post for more on Guild Wars II.