Why do you play mmo's?
This quote from the developer's blog sums it up pretty well for me.
"So, Why Make a Fantasy MMO?"
Short answer? As creators, we have the freedom to take the setting in all kinds of unique and interesting directions. As consumers, we love it.
Why do we love it? That's where it gets interesting. When we're kids, we start out life being told amazing stories of adventure, heroism, and downright cartoonish villainy. We call some of them "fairy tales," and others that have lessons get called "fables."
Later in life, we start reading stories on our own. More grown up, more nuanced tales of intrigue and treachery. We start growing attached to characters and settings. We explore these fantastic places through others' words. We crave to explore further.
At some level, almost everyone out there has the basic familiarity with at least some of the elements we use in building these worlds. They come for all reasons - To explore, to socialize, to escape, or just to take on a role and achieve in a way that simply doesn't exist in the real world. People bring with them some common level of understanding, and they can get straight to enjoying the things that make our world different.
There is the sense of adventure, the community aspect, the unpredictable behavior of people. I believe that an mmo setting allows the most out-of-the-box play, where people can be more imaginative and creative in their approach. For example, in Halo people were consecutively exploding bombs beneath them to get to inaccessible areas, beyond the intent of the developers.
A good mmo can create alot of fun and pleasure.
The short answer to your question: I play mmos for fun.