What in your opinion do you think is the one action you have taken to promote your website (commercial site or otherwise) which got you the best results ?
I'm looking to promote a website and am doing all the usual things but it's only been going for a couple of weeks so it is too early to judge anything yet, although it is already listed in AltaVista, AllTheWeb, and Yahoo search engines and has had over 500 hits.
I've done the usual Meta tags, keywords, and stuff to make it search engine friendly and I've started working on building up some quality incoming links. I set up a Facebook fan page for the site last week and I promote it now and again with status updates on both Facebook and Twitter (being careful not to spam ofcourse) and asked my friends to pop a link on their pages/status updates now and again too. I've avoided adding it to any of the free-for-all link sites as I know that these actually damage your ranking because search engines put more value on one way links than on reciprocal links and reduce your ranking if your site is one certain types of sites like free-for-all's. I'm thinking about writing an article covering the subject matter of the site and then uploading it to various article sites for other people to use as I know that this is an excellent way to increase traffic and incoming links. I might be looking into banner exchanges later but I'm not keen on that idea as I want to keep the site banner free if I can. I've made a video and uploaded it to YouTube and included the url to the site in the video description because I know that that helps with the search engine rankings and also gains traffic from folk surfing YouTube. I've added the site to some relevant Directories. I've obviously added a link to my email sig too but not to forum posts because of the nature of the site and the probability of arguments. I made some humorous images with the url to the site on them and have uploaded those to various places.
That's all that I can remember that I've done off the top of my head. You may have noticed that all the above are free ways to promote a site, that is because my site is non commercial and I don't have the funds for options such as Pay Per Click of paid for links.
I'd be very interested to hear what has worked for you as far as site promotion goes.