Sir Bruce has updated his MMOGChart with subscriber data through the end of 2005. Getting accurate numbers for these games is notoriously difficult, not leastly because different games/companies have different definitions of what exactly a subscriber or player is.
But one thing has been common to MMOG numbers for a long time: a game's biggest spike comes right after launch and tends to plateau or dip afterward, spiking again when a major expansion is released.
World of Warcraft is throwing off the curve in all kinds of ways, but a subtler revolution to this conventional wisdom may be unfolding with Second Life.
This anything-goes, DIY virtual world launched in 2003 and after a year had only about 10,000 users. Now, they're claiming 170,000 users and 20% growth a month.
Again, Second Life's definition of a user may include those who've created free accounts rather than subscribing, but with the real-currency-for-Linden-dollars market, that doesn't mean that those apparent freeloaders aren't paying customers.
The world (it's not really a game) has the benefit of a very engaged staff, regulars at industry conferences and events and on blogs, and much PR.
Not all of this PR is positive: folks are no doubt checking out Second Life for salacious reasons, following up on juicy press about virtual call girls and players' using custom avatars to role-play age-taboo fantasies.
Regardless, Second Life's healthy player base hasn't been the meteoric rise of some heavily-hyped MMOG, but has grown over time and shows no sign of slowing. Is this a sign of things to come for timelines to success for these games?
Edit: Puzzle Pirates is another one of these slow burn MMOGs. It's been out a few years and is steadily growing, faster now that they've launched an experimental and successful new business model. Both companies, Linden Labs for SL and Three Rings for PP, are lean organizations, privately held, and target the larger and more casual markets outside the typical MMOG hardcore. Maybe those elements are part of the slow burn recipe.