10.4. Cross Links
Cross linkslinks within your siteare important to visitors as a way to find useful, related content. For example, if you have a page explaining the concept of class inheritance in an object-oriented programming language, a cross link to an explanation of the related concept of the class interface might help some visitors. From a navigability viewpoint, the idea is that is should be easy to move through all information that is topically related.
From an SEO perspective, your site should provide as many cross links as possible (without stretching the relevance of the links to the breaking point). There's no downside to providing reasonable cross links, and several reasons for providing them. For example, effective cross-linking keeps visitors on your site longer (as opposed to heading off-site because they can't find what they need on your site).
One reason for cross linking is that ideally you want to have dispersal through your site. You may have established metrics in which one page that gets 100,000 visitors is doing well. In this case, 100 pages that each get 10,000 visitors should be considered a really great success story. The aim of effective cross-linking is to disperse traffic throughout the pages of relevant content on your site.