Massive Multiplayer Online games can actually be self sufficient with as few as ten thousand users. They can enter into a state of developmental dormancy. All that is required is to consolidate the hardware, decrease the bandwidth, whittle the staff down to a team of three, and bank some content patches. You can basically run the whole affair out of a small room. Sony Online Entertainment has been doing this for years. They run a number of games that are abysmal failures, and are able to do so year after year. Not only that, but according to them they are making a healthy profit.
They probably spend less then a hundred thousand a month maintaining the system. So the rest is just straight up profit. Granted if your looking to make back a fifty million dollar up front investment. You will probably never make that back, but if you can make back a million dollars a year. Why wouldn't you just continue to drag the corpse. Honestly I cannot say just what motivates some people to hang onto a obviously dead game, but there seem to be enough such types out there to keep such games going for years.
