The Daily Grind: What's the best way to keep players?

Let's say you're responsible for an MMO that's steadily losing players. Without being able to pinpoint why, you head to the forums and listen in: "PvP sucks!" "Classes under/overpowered!" "Not enough kittens!" Making the tough choices is your job, and you realize you can't address all of these concerns in time to keep a huge number of paying players from quitting forever. What do you do?

Do you offer to make the game free? If your model depends on monthly fee revenue, switching to an ad-supported model or microtransactions is no trivial matter and won't happen quickly enough. Do you grant 5x experience for a month? People won't want to level up more quickly in a game they don't like enough to keep around. What's a good solution? If your favorite MMO were to make you angry enough to leave, what would keep you?
This article was originally published on Massively.