I think it's just like Dofus. "Free" to play, a demo version basically. And you can subscribed to unlock the whole thing. I got the email a couple days ago too. I don't think it is fully released yet though, and is just a "Hey, act now, keep your name, etc".
I stopped playing after a big update a while ago ruined haven bags. I had a massive bag (tons of Gems) with lots of stored stuff all sectioned off. One update allowed people to purchase items without entering your bag. This made EVERY item purchasable even if you had your bag sectioned off with rooms only accessible to friends, guild members, no one, or only specific people. Or even if you locked your bag, people still could purchase everything from the outside. Tons of people lost lots of stored equipment and resources they had stored for little or no cost.
I couldn't use my haven bag for fear of having all my stuff stolen by some guy who walked by. I stopped playing and watched the updates hoping for a fix, but never saw one. Now I'm not sure if it's updated by have basically stopped playing all together.
Can't sleep, clown will eat me.