There is a nagging feeling to any Diablo 3 player that says “what’s next?” or “how many more skills can I unlock today?” The progression of your character and their journey pulls you in and refuses to let go. You want to know who the "Stranger" is.  You need to wander the deserts of Act 2 or look with disbelief at the palatial settings which await you later in the game. The building of friends in each act that were not available before and the growth of items you experience all lead to progress and that is incredibly addictive.