Honestly, all the numbers say is that Square is going to rake in with their fee models. Mind you, there's two tiers of payment plan, Entry and Standard. Most (if not all) can get by with Entry ($9.99) with Standard being for those that... chase servers ($14.99)? Then there's the schedules. You can go for the standard schedule (30 days) or go for extended schedules and save even more money per month. To say that this game is expensive to play is a pretty shallow argument considering how expensive it isn't. And with this many people clawing to get in I'd be surprised if they lose any kind of significant population once the free trials end. As for the Old Republic analogy, they went free to play not in response to the wild success of initial sales but due to the wild drop off of subscribers once the novelty wore thin. Same with Star Trek.
