What you're failing to consider here is that every user Halo 3 had paid approx. $60 up front to become a user in the first place. The problem with these free-mium games is that the average revenue per user is so much lower.
Exactly. There's no loyalty. Users won't hang around unless they've put something in the pot. Zynga knows this though, since it's the whole premise behind their initial success.
