Criteria Explanation A20. Internal : External link Ratio We strongly believe that the majority of links used should be internal, in relation with your site's core content/topic. Links to other sites are only acceptable if they compliment your content, or serve as additional resource to your visitors. In order to keep your visitors browsing on your site in stead of someone else's, your site should limit to have more than 15% of its links as external links. Do not depend on external resources to make your point.