[Spirit]

They are farmers, and I think they work from a bot program. They are programmed to kill mobs within a certain range of them. That is why they never speak back. They can also be programmed to "kite" mobs. You can tell this because they always run the same pattern when they kite. They are farming to get either materials to sell on those websites or to sell in shrooms to help generate their money that they give you when you pay them real money. If you ever go to one of those websites and just look around it (do not actually buy anything from them), they offer to level up your character, they will sell you silver, and all kinds of other stuff.
If you see a sell shop with one of those funny names, do not buy their stuff because you are just helping to support their websites. I am not sure if it is an actual scam, but from their websites, they look like legite companies that do this with a lot of on-line games. They have people and bots that play all day long to gather, sell, and level people. It is kind of scary how many games they are doing this to.