I joined not too long ago. I searched for free online mmorpg, browser mmorpg, and flash mmorpg. All of those searches resulted in many other hits before I stumbled across magicduel. I think the only place I heard about magic duel was on a different forum, actually. I was not satisfied with the other mmorpg I found.
I am so far pleased I found MD, but like I said it was because someone told me about it, not because I found it in google search.