First, you need to write up a post for HN, detailing what niche it was that you were trying to fill, some of the obstacles you overcame, and why you think you failed. It will be educational for you to do it, and for us to read it.<p>Second, I think you just pull the plug. You can put an announcement on your homepage, giving your users notice, and email them, as well, if you have their emails. You could even send them the post detailing your journey and why it is ending, to give them a bit of a feeling of closure, and not feeling just left out in the cold.<p>Take the code. A lot of that back end stuff that you've written, you'll build off of for your next site.<p>Good luck in your next venture. 2010 could be your year.