Despite that over-hyping Second Life has received on /. it is not that popular. While they may list 230,000+ accounts, there are not nearly that amount of active users. How can you even begin to compare the 5,000 people who find Second Life interesting enough to spend time on it to the 6,000,000+ subscribers of World of Warcraft?
As I stated, there is no market for that type of thing. The people who are interested in it are a very, very small minority.