Earlier this month, Google employee/celebrity Matt Cutts rocked the SEO world when he stated that Google does not observe the rel="nofollow" attribute the way we thought they did. In fact, they might not observe it at all. Since then, SEO professionals have wandered around half-dazed, questioning all of the beliefs they once thought were unassailable...Well, maybe I wouldn't go that far, but Cutts' comments certainly have caused a stir in the blogosphere. Rather than write about this issue right away myself, I wanted to give a bit of time for the dust to settle, as more and more issues came to light over the past two weeks. But without further ado, here is my overdue, but seemingly obligatory, post on rel="nofollow".
What's rel="nofollow"?
Rel="nofollow" is an HTML attribute that you can add to any link. When the attribute was created, Google said that if a link was marked with this attribute, they would not crawl, or "follow," that link, and the destination URL would not recieve any authority from the link in Google's eyes. Stated more simply, the site being linked to would, if nofollow was used, receive no SEO benefit from the link.
Furthermore, SEO's were led to believe that Google authority flowed through the Web, almost like electricity ("Google juice"), and by plugging the holes in your site (making links on your site nofollow), you could retain more Google authority for your own site. People even went so far as to nofollow some of the internal links in their sites in order to direct more authority to the more important or desirable pages of those sites (this was called PageRank sculpting).
Google: "Surprise! It's doesn't really work like that."
All of this changed when Matt Cutts announced at the SMX Advanced Conference in Seattle on June 3rd that Google PageRank doesn't really work like we all thought it did. Cutts' official position was that a nofollowed link does not receive any benefit from that link, but the linking site does not receive any benefit from making the link nofollow in the first place.
Previously, sites could preserve the PageRank that would flow out of an external link by making that link nofollow. Now, the PageRank that would flow to that link simply 'exaporates' when you make that link nofollow. It neither stays with the originating site or moves to the destination site.
Cutts also took the opportunity to maintain his position on internal PageRank sculpting, saying that a well-built site will do far more for you than any time spent sculpting Google PageRank through your site.
Why They Did It
Conspiracy theorists could offer a number of intriguing theories as to why Google made these changes to an attribute that they themselves created (in fact, Cutts helped create it). However, I think the answer is pretty simple. Google places a very high value on the integrity of their Index, and base their decisions on what will result in websites being assessed in the most accurate way possible by their algorithms. When people begin to use something like rel="nofollow" to try to "game" the system, Google will devalue that attribute or ignore it entirely. It's as simple as that. Google relies so heavily on links as a measure of a site's value, it is critical that they can accurately assess those links.
Where Do We Go From Here?
The key question that remains for people who were using rel="nofollow" on their sites is this: Should I make all the links on my site dofollow links, or should I leave things they way they are? Going forward, is there any value in using the nofollow attribute?
One issue that is particularly puzzling to website owners is what to do with comments in their blogs. If a blog post has 50 comments, all of the links in those comments will bring down the PageRank of the blog. Previously, this issue was addressed by using rel="nofollow" on all links in the comment section. In fact, software like WordPress does this by default. Now, many are wondering if they should turn off commenting entirely to avoid this loss of PageRank.
Google's official position, as always, is for everyone to continue to go about their business, and they will take care of the rest. But what is a website maintainer to do? For now, it seems like the wisest choice is to leave all nofollow links on your site as is, and continue to use it in the future as you have in the past. It probably isn't having the effect you once thought it was, but since it's hard to say exactly what effect it is having, this is probably the best course of action. In the meantime, keep an eye out for updates on this issue in the coming weeks.