Another way would be to join Linkedin and join groups that might have members that are interested in your site and what it has to offer. Then start monitoring the discussion threads in the groups and begin answering questions and addressing topics. If you can present yourself as an expert on certain topics that would involve your website and its offerings, people will start checking out your profile and your site. Unfortunately, your original message was edited to remove the urls or I would be able to give a more definitive answer. Could you describe the sites and their purpose and/or offerings?