Why is world of warcraft so successful?
gregstoll: Points that come to mind:- The leveling curve is just about right.  At the beginning you gain levels very quickly, and with them new and exciting abilities.  You always feel like you're making progress, be it with better spells, better gear, getting to adventure in new zones, etc.- It's very casual-friendly.  When you're logged out you earn "rest XP" which, upon logging back in, lets you level faster, so you don't have to play in large chunks of time to make progress.  It's also pretty easy to level all the way up to 70 (max level) playing by yourself.- There's a surprising amount of humor (pop culture references, etc.) which is a nice bonus.- There are lots of things to do even at max level - this wasn't as true in the past but you can do daily quests, play in one of the four PvP battlegrounds, join an arena team, do raids, etc.