Google New policy change for Backlinks: Reorganizing internal vs. external backlinks

Today we’re making a change to the way we categorize link data in Webmaster Tools. As you know, Webmaster Tools lists links pointing to your site in two separate categories: links coming from other sites, and links from within your site. Today’s update won’t change your total number of links, but will hopefully present your backlinks in a way that more closely aligns with your idea of which links are actually from your site vs. from other sites.

You can manage many different types of sites in Webmaster Tools: a plain domain name (example.com), a subdomain (www.example.com or cats.example.com), or a domain with a subfolder path (www.example.com/cats/ or www.example.com/users/catlover/). Previously, only links that started with your site’s exact URL would be categorized as internal links: so if you entered www.example.com/users/catlover/ as your site, links from www.example.com/users/catlover/profile.html would be categorized as internal, but links from www.example.com/users/ or www.example.com would be categorized as external links. This also meant that if you entered www.example.com as your site, links from example.com would be considered external because they don’t start with the same URL as your site (they don’t contain www).

Most people think of example.com and www.example.com as the same site these days, so we’re changing it such that now, if you add either example.com or www.example.com as a site, links from both the www and non-www versions of the domain will be categorized as internal links. We’ve also extended this idea to include other subdomains, since many people who own a domain also own its subdomains—so links from cats.example.com or pets.example.com will also be categorized as internal links for www.example.com.

If you own a site that’s on a subdomain (such as googlewebmastercentral.blogspot.com) or in a subfolder (www.google.com/support/webmasters/) and don’t own the root domain, you’ll still only see links from URLs starting with that subdomain or subfolder in your internal links, and all others will be categorized as external links. We’ve made a few backend changes so that these numbers should be even more accurate for you.
Note that, if you own a root domain like example.com or www.example.com, your number of external links may appear to go down with this change; this is because, as described above, some of the URLs we were previously classifying as external links will have moved into the internal links report. Your total number of links (internal + external) should not be affected by this change.