by samAs you may know, Google’s Webmaster Tools splits the list of links connecting to your website into two categories: internal links, those coming from within your site, and external links, those from other sources.
Last week Google announced some changes to Webmaster tools on their blog that affect how some of these links are categorised. The reason for the change was due to some confusion surrounding how some links were being classified. Previously, only links using your site’s exact URL would be counted as internal links. For example, if this website had been registered as digitalclicks.co.uk/example, then links from digitalclicks.co.uk/example/sample would be classified as internal, but those from digitalclicks.co.uk would not be.
This meant links from sub-domain websites were also listed as coming from an external source. As you can imagine, this would occasionally confuse newer website owners. Especially when most people would consider digitalclicks.co.uk and www.digitalclicks.co.uk to be the same site when www is actually counted as a sub-domain similar to how subdomain.digitalclicks.co.uk would be and was therefore classified as an external link.
Since the update has taken place, links from sub-domain sites are now categorised as internal links. As most owners of a particular domain will also own its subdomains, this will likely mean a welcome change. Those, however, that only own a sub-domain but not its root will see no change.
This of course means that for you Webmaster users, you may see a change in the number of internal and external links, as some of the URLs previously listed as external will now transfer over to being an internal link.
Some of you may be wondering whether this change is just limited to Webmaster Tools, what this means for Google SEO, and how sub-domains are listed in their search results. There is no mention of the changes causing any such impact on Google SEO in their blog post, but the issue remains currently unclear. Perhaps Google will enlighten us on this in the near future.