The Importance of Internal Linking Structure

Having gone through a series of SEO evaluations those last few weeks, I was shocked to come across so many cases of websites with bad internal linking structure.   I now think it's essential to stress on good internal linking since I have the impression that web designers often overlook the importance of having a well structured site in terms of internal linking.  The current situation is very sad since a lot of websites are not benefitting of the power of internal linking.  I therefore compiled a short list of factors that one should consider while building the website structure.

Good Navigation - The most important issue here is to make sure that the site navigation is correctly spidered by the search engines.  We can ensure this by either use of anchor text and text based navigation, or an image-based navigation type with significant 'alt attributes' attached to every image link in the navigation.  Avoid Javascript and Flash navigations because they are still not well crawlable and spidered by the search engines.  If you still want to keep your 'flashy' navigation then I'll suggest you include an alternative navigation that would be spidered by major search engines. For example, you could have a text based navigation at the bottom of your page, this will help you inner pages be more spiderable.  

XML Sitemap - I cannot stress enough on having a good XML sitemap on your website.  Sitemaps provide an overview of the site at a single glance but at the same time they help search engines crawl the website.  Submitting a XML sitemap to Google Webmaster Tool for example can be very useful since it gives the search engines a concise format that provides spiders with a super-fast blueprint for indexing a website. Furthermore, sitemaps also improve web usability as they are an alternative form of a site specific search, which brings users to the information they need quicker.  

Breadcrumbs - I believe breadcrumbs are excellent internal linking tools. Being 'links' by nature, they aid with internal linking and consequently increase the search engine visibility. In addition to anchor text differentiation, breadcrumbs are very useful since they increase the general usability of the website by allowing users to know exactly where they are on the website.  

Links in Content - I had the chance to analyse different kind of websites in different industries but it was quite common to see a lack of links in their copy.  It's essential to have in-content links, since not only they are more likely to have higher click through rates (increased confidence path), but they are also capable to add more significance to a link because of the neighbouring text.  Therefore, the rule of thumb here is to have links with anchor text with targeted keywords in the copy of the website.  

Links to Important Pages - It's essential to always ensure that all important pages are well linked to other pages on the website.  I sometimes found it amazing how some of the most important pages of a website are not properly linked to other pages.  It is better to link them directly to the homepage so that they can benefit from the power of link juice passing from the homepage.  But time and again I see websites with important pages buried too deep and ending up with no page-rank at all.  And it's not uncommon to find those pages not indexed by the search engines.  

Cross-check Robot.txt - This may look stupid, but I came across cases where I found important pages of a website not being crawled and spidered because they were found in a section where the robot.txt was preventing spiders to crawl.  This mainly happen by mistake or when new pages are added to the website.  Sometimes webmasters tend to forget to go back to their robot.txt and check whether all crawlable/non-crawlable sections are up-to-date.  In brief, your important pages need to be findable, if not there's no way they'll get crawled and indexed.  

Linking Policy - It is very important to be extremely consistent in your linking behaviour. What I mean is that while linking pages we need to be meticulous about how we are building the links.  I once had to re-build the links of a whole website since links to the homepage were very inconsistent.  Some links were pointing to the .com page whereas others were pointing to the .com/index.php page.  The website also had some major canonicalisation issues where several links were pointing to identical pages but with different URLs.  Cases like this actually decrease all the power of internal linking since the link juice is diluted around the site instead of being intelligently focused on the essential pages.  In brief a link policy should be setup so that everyone building links knows exactly how and where to link them.  

Just to remind, good internal linking ensures that all pages on your website get properly spidered and indexed on search engines.  It increases the relevancy of a page to the targeted keyword phrase.  Allows proper link juice passing to internal pages hence increasing their page-rank. That's it, hope that this helps tuning and enhancing your internal link structure.