It’s been about two weeks since this Gamasutra interview with Jeremy Gaffney, but I think it’s still worth a read. Or just have your mind blown with this thought experiment:

“Even a good game churns 5 percent of its users out every month,” says Gaffney. “That means every 20 months you’ve churned out your whole user base.” If you have one friend who still plays an MMO, that means you might have 10 friends who used to play that MMO.

That 5% monthly figure has been pretty consistent over the years, as WoW had an apparent 4-5% churn rate even during the heights of vanilla/TBC. That means each expansion could basically have an entirely new playerbase. Obviously, some stick around for the long-haul, so there’s some continuity.

Nevertheless, I feel like this more succinctly highlights the design pressures on MMO developers. Does an MMO ever get more hardcore over time? It’s hard to see how it could, given how one needs to entertain an entirely new audience every (at best!) two years.