Guild Wars 2 developer ArenaNet has temporarily ceased selling digital copies of the game as too many concurrent players were beginning to "compromise" the game.

"Ensuring the best possible play experience for our fans is our highest priority," said an update posted on the game's Facebook page. "We've said before that we would be willing to temporarily disable first-party digital sales if we felt our high player concurrency may compromise player experiences."

"We have now reached that point," said the post. "Effective immediately we have disabled sales via"

Players will still be able to buy copies of the game elsewhere, however. "To be clear, box and digital sales are still available via our retail partners. We are tracking our concurrency closely while expanding our infrastructure. We'll re-enable first-party digital sales as soon as we feel that we can do so safely."

So... Guild Wars 2 is popular, then?

Guild Wars 2 launched officially this week, and saw over one million people pre-purchase the game to take part in a three-day headstart weekend which saw 400,000 concurrent users. This has, perhaps understandably, caused the servers to be subjected to heavy load, with Guild Wars 2 using a server overflow system so that players don't have to stare at frustrating queue screens. ArenaNet says it is working 'around the clock' to make it so that players aren't affected by overflow servers, however.