Many years ago I put my site through a re-design. I worked hard to make sure everything was done just right, including the images and navigation. But one thing I failed to consider was internal linking, separate from the navigational elements. It wasn’t until much later that I realized how much traffic I was losing because my internal linking was (or lack thereof) wasn’t benefiting my visitors.
In-site link implementation can make a considerable difference in how effective your optimization campaign is. Or isn’t. While your site’s primary and secondary navigation is extremely important, you shouldn’t make that the only way for visitors to get around your website.