For about six years after its early 2005 launch, it looked like there was nothing that could stop the runaway success of Blizzard's World of Warcraft, which grew to a peak of 12 million paid subscribers by the end of 2010. Since then, though, the game has seen a long, mostly uninterrupted slide in its player numbers, with only 6.8 million subscribers as of July.

Blizzard obviously isn't happy about this trend for one of its biggest products but seems to have accepted that things aren't going to change any time soon. "We really don’t know if [World of Warcraft] will grow again,” lead game designer Tom Chilton told MCV in a recent interview. "It is possible, but I wouldn't say it's something that we expect. Our goal is to make the most compelling content we can."

A new expansion pack like the upcoming Warlords of Draenor could juice those subscriber numbers, as previous expansion packs have seemed to do. Chilton seems to see a bit of diminishing returns in this strategy, however. "By building expansions, you are effectively building up barriers to people coming back. But by including the level 90 character with this expansion, it gives people the opportunity to jump right into the new content."

Chilton is referring to Blizzard's controversial decision to allow players that purchase the new expansion a free character upgrade, which allows them to immediately access new level-restricted content and to purchase that level-up buff separately for secondary characters. On the one hand, this new feature does indeed make it easier for lapsed players to jump right in without the need to grind up to the new content in the expansion. On the other hand, it could make it more likely that players simply rush through the new content and then let their subscriptions lapse yet again. If players aren't sticking around once they've seen the new worlds and bosses, the expansion model probably isn't sustainable.

Even if World of Warcraft is now in a state of permanent decline, it's worth admiring how successful the game's run has been in the notoriously fickle world of MMOs. Many other MMO makers would kill to even approach WoW's currently diminished number of 6.8 million subscribers, and Blizzard has managed to maintain the game as a subscription-based business even as the MMO genre overwhelmingly shifts to a free-to-play model. We wouldn't be shocked if there's still a significant number of players happily roaming the realm of Azeroth in another ten years, even if the size of that player base will never reach the dizzying heights it did just a few years ago.