You also get to update the site with your word count, which, at least for me, provides immense satisfaction.
NaNoWriMo is most famous for its event in November, where participants write 50,000 words (or a first draft) in a month. But users can access the site at any time during the year! Put in your target date and your word count goal, and the site will tell you how many words you need to write every day to make it happen. You also get to update the site with your word count, which, at least for me, provides immense satisfaction.