I just recently got back into this game and learned how addictive it can be. You will spend hours leveling up characters via 'cow runs' and trying to find elite items that can be traded or sold on Ebay. This game will sap your time away like no other.
At first the game might seem pretty basic with its click-based dungeon hacking gameplay but then you start to realize that each character has their advantages and disadvantages and you notice how much you can customize your character and really feel like you brought up your character the way you wanted to.
The game can be occasionally annoying cause BNet will frequently lag like hell, but once you get past that, it's a great game and very in-depth once you look past the surface.