They're pretty big in Korea. They are gated (like Hiveworks) and do not let you upload your work there unless they've picked you and signed a contract with you. I have an account there as a reader, though it should be noted I use their Korean site and read the comics in Korean.
I really like their early release system. There's plenty of incentive to pay, even though you can read most (not all) series for free if you wait around enough. It's a great compromise between free to read and pay to read.
Maybe they need to market themselves more/better outside of Korea, though, if their English site is to survive and grow.
