NaNoWriMo is about a social writing experience. It's about writers setting a goal and helping each other achieve it. It's about community and encouragement. It's a celebration of writing in general, be it for fun or profit. And it's about winning.
NaNo isn't really a contest (though there are sub-contests). The goal is to write 50,000 words in one month. If you do that, you win. Doesn't really matter if it's one book, several stories, or just random words on a page (though what's the fun in that?). If you write 50k you win. It doesn't have to be polished, ready for publication. It doesn't have to complete the novel. And even if you don't quite reach 50k you'll still win. That's the point - writing itself is a win.
I'm participating for the first time and I'm starting to get excited about it (just finished up a draft of my WIP so I'm shifting gears now). I've chosen to write a Necessary Evil tale. My previous ones have been novellas around 25k. So for NaNo I've chosen an idea that has a little more meat on its bones. I've also chosen a new main character (though the unnamed man will still be there). Here's my novel:
Tarya watches from hiding while her entire family is slaughtered by an assassin sent by Lord Faromar. She flees for safety but her only thought is for revenge. But what hope does a sixteen year old Baron's daughter have of defeating a skilled swordsman and powerful lord? For that, she must transform herself into a weapon.
She seeks out the greatest fighter in the land, known simply as the Master. When he will not train her she finds other tutors: a street urchin who teaches her how to survive, a castle guardsman who trains her in swordplay and gives her his heart, a foppish prince who's a master fencer and cruel lover. Her journey is dark, but the light at the end is the death she holds for those who've wronged her. She will have her revenge if it costs her her life. Or even more.
Good luck to everyone who's participating in NaNoWriMo (including me). See you on the other side.