Search Marketing

Google Changes “Nofollow” Policy, No Longer as Effective for SEO

June 5, 2009

Google’s Matt Cutts recently said the nofollow SEO technique will no longer be as effective.

This week at SMX Advanced, Google’s high-profile head of Webspam and liaison to search marketers worldwide, Matt Cutts, pulled the rug out from under SEOs and Webmasters everywhere when he suggested that a previously sanctioned search optimization technique heavily relied upon by many site optimizers would not be supported in the same way. In short, he stated that the nofollow attribute that is considered helpful in preventing spam and even sculpting a site’s PageRank would no longer be as effective.

Who does this affect?
Because the active use of nofollow is a more advanced SEO effort, this change won’t affect the majority of search optimizers. However, the popular blogging platform WordPress (used by this blog) uses nofollow on links left by commenters, so every WordPress blogger is potentially affected.

Google has long recommended the use of nofollow when linking to content excluded via various exclusion protocols; Webmasters who have followed Google’s guidelines are now up a creek. And finally, advanced SEOs who use nofollow links to sculpt their PageRank will certainly be scrambling to modify their sites.

How is nofollow used?
Originally, site optimizers started link spamming forums, social media sites, profile pages and just about everywhere else they could leave links on other peoples’ sites in order to increase the number of links pointing back to their site, hoping this would improve their site’s relevance and PageRank.

As a response, Google began to support a link attribute — instruction embedded into a link — that told the Google crawler not to follow links labeled with the code rel=”nofollow”. These links became invisible to the Google crawler so they don’t negatively impact the page they are placed on. Many social and community-based sites jumped on the nofollow bandwagon.

Eventually, search optimizers learned how to use nofollow to their advantage on sites they directly controlled. By nofollowing links to pages that were not deemed important in terms of traffic generation, they could reserve more “link juice” for the other, more important links on the page. In other words, they were sculpting their site’s PageRank. This funnels link juice to the pages a marketer deems most important (such as a Products page) so they can be boosted higher in the search engines, and away from less important pages (e.g. About and Policy pages).

The official advice from Google has always been that, while this is feasible, it’s not an efficient use of a site developer’s time, preferring instead that they focus on the site content, positive user experience and a strong natural linking structure. However, in public forums (Google Groups discussion) and interviews (Stone Temple & SEOmoz), Matt Cutts had expressed that using nofollow actually does have its place. So, it comes as a surprise that Google is now changing its policy.

What is the impact of the change?
According to Cutts, the new policy has already been put into effect. Links that previously benefited from having large amounts of PageRank funneled through them will now only get their “fair share.”

Given a page with a PageRank of 4 with 8 outgoing links, each link will receive an equal PR, or .5:

.5 –> .5        .5 –> .5
.5 –> .5        .5 –> .5
.5 –> .5        .5 –> .5
.5 –> .5        .5 –> .5

By using nofollow on 4 of the links (prior to the change), each link that was nofollowed gets 0 PR, and the remaining links split the total PR, thus increasing their respective rank:

1 –> 1        0 –> 0
1 –> 1        0 –> 0
1 –> 1        0 –> 0
1 –> 1        0 –> 0

Now, when using nofollow on 4 of the links (after the change), PR for each page will look like this:

.5 –> .5        0 –> 0
.5 –> .5        0 –> 0
.5 –> .5        0 –> 0
.5 –> .5        0 –> 0

The nofollow links still aren’t counted by Google, but they also no longer contribute any link juice back to the 4 links that are being tracked. Therefore, the PR for these 4 links goes back to where it would have been without the nofollow attribute.

This has large ramifications not only for the Web site optimizers who relied on this technique and now have to go fix their sites if this pans out to be true, but potentially even for all the social media sites who use the nofollow technique to fight spammers and are now losing a significant amount of their ability to impact natural search results.

These social media, community-based and user-generated content sites don’t have complete control over their content. That is not the fault of the Webmasters, but something inherit in the medium of user-contributed content, and for the most part, it furthers the discussion and expands the Web. (For instance, if you leave a comment on this blog post and enter a URL, we’ll link back to your homepage, because it’s the polite thing to do.)

Nofollow is a necessity for blogs and other social sites; to leave the community open, there must be an effective mechanism to fight spam. If sites do start to see a decline in their natural search rankings, they will fight for their own preservation and start to remove outbound links altogether, possibly contracting the Web and throwing a huge wrench in social media and the open community concept.

– Mike Levin and Mari Assefa