What proportion of people actually replay games?

About a year ago, Stardock disclosed that only 23% of people who bought Demigod – a game designed primarily for multiplayer! – even attempted to play online. (The link goes to Rock, Paper, Shotgun’s write-up, because the original link to the Stardock document is dead.)

Now, multiplayer is a huge selling point for games and a huge rallying point for hardcore players of individual titles.  But if that 23% is at all representative of gamers in general, it makes me wonder how many other bullet-points go ignored by the vast majority of players.

Take replayability in the case of “single-play”/”narrative”/”campaign”-type games (which includes everything from Fallout 3 to Monkey Island – I exclude “scenario”-type titles such as Civilization or chess in which you play many discrete ‘games’). There are people out there who play the same RPG for hundreds and hundreds of hours, trying out different origin stories (Dragon Age), different branches to the storyline, good/evil solutions to quests, postgame or New Game + content, etc. What I would like to know is, out of those players who have already finished the game, what proportion do the replayers represent? Is it closer to 23% or 77%? I’d love to see some hard data on this topic.

And, for the record, I neither replay games nor (with a few limited exceptions) bother sticking around for endgame content. Once I’m done with my first playthrough, I’m done, and it’s time to bid farewell to the world and characters and move onto the next game.