Comment on Comments WordPress SEO Plugin by SEO Dave.
Had a very quick look at your site, you don’t appear to have any comments at this time. Without comments the comments plugin has nothing to work with, so right now your site won’t benefit from the comment plugin.
Try adding a comment as see if a link appears at the bottom of the comment you make. Similar to the link on this comment with anchor text “SEO Comments Plugin Needs Comments” (I use a more advanced version of the free Stallion WP SEO Comments plugin).