Build a network. Use a reasonable email-list system. Don’t spam but give the users the possibility to sign up for your newsletter. Use the well-known techniques like Facebook campains or Linkedin.

Try to image what your customer expects. What would they like to know or read. Your website is not a brochure. The visitor on your website expects to find an answer to a question he had. Participate in newsgroups and forums. Not to promote your site but to learn and listen and build your network.