Well, actually, it makes a lot of sense after a hile... when you buy the game you get 30 days included. There's a lot of services that need to be paid monthly, it helps the game to evolve and mature, you get support, improvements, and tons of other stuff you wouldn't get if it was pay-once, play for life (they would simply release upgrade packages to compensate every 6 months, that wouldn't be better and would cost a lot too).
That being said, paying for online gaming also has a very important advantage: you remove a lot, and I mean a LOT of people from the game who had nothing to do there in the first place. Other online games have tried different approaches in the past but everytime you get free unlimited access, servers are flooded with people who just annoy the hell out of everyone and destroy the gaming experience. If you require pay for access, then most of those people go somewhere else.
I hope I'll see some of you soon
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