MMOs with a heavy Asian orientation tend to be very deceptive in their player base. What people fail to realize is that for a very long time your typical Asian player was doing these games from Internet Cafes with names like "Bangs" (which I think is the Korean term). Personal computer ownership is only now beginning to increase, which is why I think China and other nations have started to pay more attention to the flow of totally unregulated information (ie they don't just have to regulate businesses anymore).
At any rate, check it out on Wiki how memeberships even for some big games like WoW are handled there and you'll see some definate differances in attitudes compared to American marketing.
The thing is that an Asian player will go to a cafe and decide to try the various "free" games to see which ones they like. When new stuff comes out they are of course going to try it to see if they like it. They only stay to play and invest money from cash shops into the ones that they really like.
For the sake of conveinence these companies also keep their accounts open.
So basically when you look at a F2P RPG like Runescape (which I believe has Asian access) your dealing with accounts based on what amounts to the traffic at a Starbucks. It just means that many people tried the game, not that this is how many people played it.
Consider that in comparison it's a bit more difficult to just "try" WoW despite the relatively recent development of "Trial Accounts" (which are a bigger pain to use than asian F2P games especially considering the DL times which might not be an issue at a cafe that has everything installed). For most serious western MMORPGS you pretty much have to pay $20-$50 for software unless your lucky enough to get into a beta.
Even with WoW with things like trial accounts, it's comparitively more complex.
I think games like Runescape, Ragnarok Online, etc... have a huge number of accounts from people who "browsed it" but comparitvely tiny amounts of active players.
I could be wrong but I believe EVE and WoW are the two games that actually have massive crowds of ACTIVE players.