You know, MMOs are pretty tough to do successfully. Instead of crafting a 10-20 hour experience, the developers are expected to make something that you'll be coming back to for months and months, with a core crowd that may sustain the title for years. World of Warcraft, for example, started with about 1500 quests. That's one thousand five hundred quests. Granted, the overwhelming majority of those boil down to "kill this dude" or "get this stuff," but it's still a heck of an achievement, and the number of quests quickly ballooned. I think what gives WoW its strength is a combination of the novelty of exploring the Warcraft universe on foot, the delightful and varied art style, and its sense of humor. That and hundreds of servers across the world to satisfy what is probably approaching five million subscribers at this point.