SEO is great but once in a while you should pause to make sure you are not neglecting your non-SEO efforts done to promote your site. Some of the things you SHOULD definitely be doing if you are not already doing it now would include:
Using social media sites – There are tons of social media sites out there. If you are not a member of one you should at least consider joining the most popular ones like Facebook and MySpace. You should also look into industry specific social media sites and join those to develop contacts not only with prospective clients but also to keep touch with the latest developments in your industry.
Blog - Chances are you already have a blog but I can’t help but emphasise how much a blog can contribute to your site. It’s not only a way to get fresh content up frequently, which is the SEO aspect, but it is also a good venue for keeping your regular customers/visitors updated about anything you (and they) deem important.
Promote your site the old fashioned way – Do whatever you can to promote your site. Use bumper stickers, posters, give away your business card, sponsor a charity event, etc. Whenever you have an opportunity stamp your website URL to let people know they can find you online.
There are lots of other stuff you can do to promote your site. Feel free to give suggestions in the comment section!