On the fifteenth of this month, Matt Cutts, the head of Google’s Webspam Team, wrote a blog post entitled PageRank Sculpting in which he clarified the Google policy regarding the use of the rel=”nofollow” attribute. Nofollow is a common SEO tool used to block the flow of PageRank. Armed with this new information, we bloggers need to change the way we look at linking and the use of rel=”nofollow”.

The Way nofollow Worked Before

The traditional way of thinking about PageRank and rel=”nofollow” was that by selectively using the nofollow attribute, one could sculpt the release of PageRank from one’s site. For example, if your site’s home page has a PR6 and you had six outgoing links, then each of these links would be receiving PR1. If on the other hand, you were to apply a rel=”nofollow” tag to four links, the remaining two links would receive PR3 each.

PageRank sculpting meant that a webmaster could sculpt the sites release of PageRank to emphasize top money making pages without overuse of visible linking.

The Way nofollow Works Now

In Matt’s article, we learned that Google made a small change to the PageRank equation which has major ramifications, especially for bloggers. Here is the gist of the issue: one year ago, Google changed its equation such that nofollow-tagged links are now included in the averaging for outbound PageRank, even though the PageRank is blocked from flowing through those links.

Using our example from the last paragraph: your page with a PR6 contains six links with four containing a nofollow attribute. Instead of the PageRank being consolidated and passed on to the two remaining links in 3PR streams, the full six links are averaged against the available PageRank making 1PR per link. The two links without nofollow attributes, receive their 1PR, while the remaining four are blocked.

How We Used nofollow Before the Change

In the past we used the nofollow attribute in two ways:

I made the choice not to alter the WordPress default setting, which applies a nofollow attribute to links posted in the comments section by visitors to the blog. This was both to restrict the loss of PageRank in unintentional directions and to restrict links between this site and sites we’ve never visited and therefore did not personally endorse.

The second way we used the nofollow attribute was to direct the flow of PageRank from this site to internal pages and other sites we wished to endorse and to block its flow to sites we felt had no need of our endorsement. As an example, when I wrote a tutorial some time back about incorporating a jQuery slideshow into WordPress blogs, the article included links to several jQuery plugins. These plugins were authored by individuals who published them freely. In my mind, this made links to there sites perfect candidates for a small PR endorsement from this site. Alternately, when linking to large commercial sites, I often applied a nofollow attribute to the link, as our endorsement had little value to them and would be better help to others.

How Should We Use nofollow Now?

With our new understanding of the Google policy regarding nofollow, we will be making (and I am recommending to you) some changes to the use of rel=”nofollow”.

To begin with, the use of this attribute to sculpt the flow of PageRank will no longer be effective. Because all links will affect the strength of outbound PageRank, it will be more important then ever to direct links from your blog’s content to sites you wish to associate yourself with. One topic Matt covered in depth was Google’s preference for sites that link out to other reputable sites and the importance of avoiding links to spammy sites in bad “neighborhoods” on the web. With this in mind, it will be important to continue to provide high quality content that references other publishers of high quality content (we should not worry about nofollowing some and not others). Google will divide PageRank the same regardless of our efforts to steer rank.

This brings us to the second topic, which is the careful exclusion of unnecessary links. As bloggers, we have two primary page types we need to consider.

Frontpage PageRank

At the top of our blog’s page hierarchy sits the homepage. This page is the primary repository of PageRank on most blogs and should be our top priority with regards to outbound PageRank.

Because we want the bulk of our homepage PageRank to pass through to our own posts and pages, I am recommending a careful pairing of some outbound links. In the past, these links could be included without substantial loss of PageRank by using the nofollow attribute. Now we need to look at every link as a dilution of our PageRank, and therefore limit their number.

By limiting the links on your blog’s homepage to internal links and a select group of outbound links, you will take full advantage of your blog’s frontpage PageRank power.

Post/Page PageRank

The second level in our blog’s page hierarchy are the posts themselves. There are two ways in which to look at posts and their corresponding PageRank:

The first is to limit the number of total links and to pass on post-level PageRank to other posts and pages. The issue with this is that by allowing comment author links on posts, you know that any well-commented post will be inundated with links. This could be resolved by removing the author links, but this would greatly degrade the user experience of your blog as well as remove one of the primary motivations for vibrant commenting.

The second approach is to look at post and pages as terminal PageRank lines. Yes, internal linking will still provide a flow of PageRank from one post to another, but that PageRank will be divided among all the content links as well as the comment author links. I personally don’t think this is an issue. The value of an active readership that feels motivated to comment far outweighs the dilution of PageRank that will inevitably occur.

Thoughts on Comment Author Links

One argument is that while PageRank is going to be divided across all links, including comments, then why not allow PageRank to follow comment links? There are many who strongly believe that comment author links should be rewarded with this PR value for their participation. These arguments were no less prevalent before the latest changes than they are now, and there is a lot to be said for this approach.

There is one issue I urge bloggers to consider before allowing the passage of PR through comments. While you may know and vouch for some of your blog’s readers, you will most likely not know most of them, and each PR-passing link will act as a vote of confidence in Google’s eyes. This will inevitably lead to intertwining your blog with those which you might otherwise choose to avoid. Additionally, widespread use of “dofollow” on comment author links will increase the effectiveness of comment spam.

Final Thoughts

Here at Ars Grafik, we will be continuing to use the rel=”nofollow” attribute, but with a shift in our goals. We will no longer try to selectively block PageRank passage to some sites in an attempt to heighten it’s strength to others. We will allow all internal links to pass PageRank freely. We will apply the nofollow attribute only to links whose destination we are not desirous of affiliation with. For this reason, we will not allow passage of PageRank to comment author links. It’s nothing personal, we just don’t have time to check out every author’s site.

There are many ways to approach this topic. In this post I’ve tried to explain our take in hopes that it may help other bloggers form their own set of “nofollow” attribute guidelines.