Most MMOs are essentially "skinner boxes."  
<a href="http://en.wikipedia.org/wiki/Operant_conditioning_chamber#Skinner_Box" rel="nofollow">http://en.wikipedia.org/wiki/Operant_conditioning_chamber#Sk...</a><p>Different MMOs have different levels of skill needed, as well are aimed at different audiences. Warcraft is aimed at "easy mode."<p>Ultimately, they are still "grinds."<p>Some games have lots of other little games, one that does a good job of having alternative schemes for advancement is a game called Vanguard. The diplomacy "mini game" is pretty interesting and I think was very innovative. If you are developing your own MMO, I seriously recommend playing VG to see diplomacy and how they've made crafting different. Sadly, VG is still buggy and the amount of people playing is dropping, and combined with the dearth of support for the game from Sony (Everquest is still the star at SOE) for VG, it will be around as long as the subscriber numbers stay high enough.<p>Disclaimer: I've played Vanguard on and off since beta (this handle is the name of one of my characters on Seradon), and I think it has great promise, however the game is a case study in how <i>not</i> to do things in the MMO industry.