In Part 1 of this two-part article series, I summarized Matt Cutt’s explanation of Google PageRank. Today, let me address his views on ‘PageRank sculpting’ – in particular, the use of the ‘nofollow’ attribute in links to control the flow of PageRank.

The ‘rel=nofollow’ is a tag you can add to the HTML code describing a webpage link. Google introduced the nofollow tag in 2005 to annotate links with the basic message to search engines that, in Matt Cutts’ words, “I can’t or don’t want to vouch for this link.”

Matt Cutts says that nofollow links definitely do not pass PageRank nor anchortext. Some SEOs and Internet marketers have disputed this, arguing that nofollow links have, at the very least, passed anchortext.

Matt admits to having seen a few instances where a nofollow link has passed anchortext. He says these were normally due to bugs in indexing that were consequently rectified.

I’m not sure this will appease those who have found otherwise, but Matt emphasizes that, in any case, nofollow links don’t help sites rank higher in Google’s search engine results.

As previously discussed in Kikabink News, Google subsequently changed how it dealt with nofollow.

Originally, given a webpage with, say, 6 inward links, none of which have the nofollow tag, one outward link with the nofollow tag, and two ‘normal’ outward links, the PageRank flow would have been 6 divided by 2.

This is because the nofollow link would not have been counted in the denominator. As such, two links would have flowed 3 points of PageRank each.

Over a year ago, however, Google changed how PageRank flows so that ALL outward links (including those with the nofollow tag) would be included in the denominator. The nofollow link, however, would still not convey PageRank.

In other words, the equation is now 6 divided by 3, resulting in the normal links conveying 2 points of PageRank each, and the nofollow link conveying no PageRank.

The upshot of this is that using nofollow to increase the PageRank flow from normal links on a webpage no longer works. Those links without the nofollow attribute will not have any more PageRank to convey than they would if the other links did not have the nofollow tag.

On this basis, the only real point in maintaining use of the nofollow tag may be to stop the search engines from following certain links because you don’t want them indexed (although a more reliable way of doing this is to use a robots.txt file or a robots no follow tag in the HTML of the webpage).

So why did Google make this change?

Matt says it’s because using nofollow caused some sites to exclude high-quality information from Google’s index (i.e. Google didn’t like the idea of people distorting natural PageRank flow).

Matt says that webmasters and Internet marketers shouldn’t try to change how PageRank flows within their websites, and should, instead, focus on creating great content that naturally attracts links, as well as ensuring their websites are useable by humans and crawlable by search engines.

So that’s the word on how Google PageRank works, PageRank sculpting and nofollow… for now.

Source: Matt Cutts, “PageRank sculpting,” Matt Cutts Blog, June 15, 2009

This entry was posted on Tuesday, June 23rd, 2009 at 12:00 am and is filed under Kikabink Lab, Search Marketing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.