Use Original Content
Writing articles for other sites that themselves attract a great number of hits can be a very effective way of attracting more visitors to your site (both directly and indirectly, via search engines). Do not forget to include your URL clearly within the content of the article.
A wealth of Web sites make content (articles of interest to people in your industry, or to your customers) available free to anyone looking for content or articles for their own Web site(s).
Check out sites like http://www.goarticles.com and http://www.findarticles.com. Making your own articles available via such sites can be a good way of getting your Web site address on many Web sites, accompanied by an article that conveys your expertise.
If you are looking for additional content for your own site, use these sites to search for the most relevant content.