For SEOs, internal links are great since they will directly affect your rankings for these reasons:
They control the flow of link equity flow (based on Google's PageRank) around a site - pages within your site structure which have a higher PageRank tend to rank better
The anchor text within the hyperlink tells the search engine what the destination page is about. If a link contains "click here" or "more" this won't work as well as if a specific product or service name is included.
Images which are linked to other pages use the "Alt text" help determine which keyphrases the page ranks for
You control these links unlike backlinks from other sites so you can feature different terms in the anchor terms based on the phrases you are targeting
What types of internal links are there?
Not all links are created equally. When Google was launched they were treated the same, but you'll see in the video below that some links are more important than other links.
Links within body copy on particular pages - editorial links
Navigational links
Footer links
Blogroll links
How do Google advise to use internal links?
If you are considering learning more about internal linking and updating your strategy you should start by checking out this video from Matt Cutts of Google - we think this is one of the most important ones for SEOs to watch 🙂
You can see that editorial links, which are links that are not in the navigation across the site are treated differently. Reading between the lines in this video, we can see that Google treats links which are across the whole site differently, so local links within individual sections can be more powerful especially when within body copy. So we suggest that:
You optimise & make use of editorial links within the body copy, so try to link using these with relevant anchor text
Consider other forms of linking which aren’t across the run-of-the-site such as within a section can be more beneficial, sub-navigation is one example of this
Implement footer links by section as well as key pages instead of having the same footer links across the whole site
Links from a common navigation on another site such as a blogroll listing sites on a blog are also less valuable so consider their place on your site carefully.
Maybe put the "nofollow" tag on less critical links which don't relate to products or services since they will detract from the key links you have!
Do you have any other ways of using internal links to help with SEO? Please share your tips?