It also got a massive amount of early hype by being a Blizzard/Warcraft IP and not generic fantasy. All of the buzz surrounding it prior to launch was about be

It also got a massive amount of early hype by being a Blizzard/Warcraft IP and not generic fantasy. All of the buzz surrounding it prior to launch was about being able to play as characters from the Warcraft universe, not that it was a polished MMO. The IP got people to sign up, the polish made them stick around.