So I just canceled just a few hours ago, maybe this thread doesn't quite fit for me, but the one thing that kept me from canceling months ago, when the game started to get stale was my guildmates. The malaise started back in Dragon Soul, got tired of playing the game, tired of LFR, dailies (yes, even Cata dailies) and of the game in general, but I stuck it out because MoP was coming and I was hoping MoP would freshen things. It did, temporarily. Changed mains, hoping to freshen things.
But if anything kept me going more than the new expansion or changing mains, it was my guildmates.
Alas, it's come to the point where I'm no longer maintaining my sub.