I don't agree, as this assumes that most people just stumble onto the game.
I left AT and EC for BT as soon as I could. 14 days for AT, and a bit longer for EC as finding the gold was a bit harder. Why? Because the guy that invited me to the game played there, and recommended that I join him.
Then, all of the people I've invited to the game did the same. Sometimes just 1 character, and the third always necessarily stayed behind, but they too migrated to BT after 14 days.
I think invitations play a huge role in recruitment, and that these players are much more likely to stick around than everyone else. In fact, I think it's a question that should be asked when one joins the game, for statistical reasons.
That's only for BT, where you can only immigrate to. I was referring to "real" immigration, where you immigrate because you feel that your realm is not fun or you want to experience other realms.
