Starting your own affiliate program can go really far in helping you market your business. Getting customer testimonials, making sure your website is search engine friendly, using a variety of methods from posting regular content on your site, to article marketing, to blogging, to social networking, and adwords...
There are so many ways to market online many relatively cheap and even free.
One thing to do would be on places that allow it, make sure you always have a link to your site on your signature line in your posts, your emails, your business cards, everywhere....
It's not spam to have it in your signature line as long as you're participating in conversations and not solely marketing.