Holy shit, why are all the F2P Games so amazing for the most part nowadays.
Honey n'vinegar, brethren. The best (if perhaps not the most effective) way to get people to give you money is to do something impressive, and then make giving you that money as painless as possible, while giving them as few reasons
not to as you can. Quality attracts financial quantity. Sometimes.
What you're seeing is a business model, one of several that's currently competing for a (still fairly) new market. One of my preferred business models, t'be honest

Anyway, in the process of downloading. Last time I tried (during the closed beta), the only computer I had access to couldn't run it. This'un's a bit more game capable, so... we'll see. Sometime tomorrow, when it finishes downloading.