IncGamers - The Humans-Only Mistake.
Ok, enough pedantry. I'm sure you're seeing the trend here and, if you've read my prior articles, you know what I'm talking about: the “humans only” error. Basically, if you're publishing an MMO in which players can only play as humans, you are alienating a significant portion of your potential customers. There is simply a large number of players that want to play gnomes, trolls, or other equally exotic characters. If you, as a developer, don't extend that option to them, they simply won't play your game.