DarrenHaye, one of our new moderators on the SEO Chat forums, posed the question in a new thread. “Google doesn’t use NoFollow links in terms of SERPs, but does it use them in identifying webspam?” he wondered. The idea was this: would Google assume that a nofollowed link leading to your site was dropped as part of comment spam, and that therefore the site it led to was spammy?
This question incited quite a bit of discussion among our regulars – including some that departed from the traditional “no incoming link can hurt you” stance. Long-time SEO Chat member tstolber stated “I believe that Google does use them to some extent when looking at a back link profile…I do believe that having too heavy a nofollow back link profile with irrelevant links CAN devalue” the authority of your website. He noted that “recent evidence (lots of analysis on Penguin) shows that there is some correlation between nofollow low relevance back links and sites being devalued.”
DarrenHaye continued his research and found a quote on the Google Webmaster Forums that indicated using the rel=”nofollow” attribute is as good as deleting a link for purposes of the Penguin update. The sense I get from this is that if the nofollow was added later, you lose whatever link juice you got from it – but if you’d been penalized for that link (for it being “unnatural,” perhaps), you’d also lose the penalty. It’s as if the link no longer exists, for those purposes.
Another long-time forum member, gazzahk, brought his perspective to the discussion. While he noted that Penguin did change the way link juice was valued, nofollow links pass along no link juice to begin with. So owners of websites who think they’ve been affected by having too many nofollow links pointing to their sites might be deluding themselves. Say site A sees a drop in its rankings and traces it to Penguin. The owner checks his back link profile and spots a lot of nofollow links. He blames those. But he’s wrong in this case.
Sites B, C, and D are linking to site A. These are not nofollow links; they’re passing link juice. However, a whole bunch of spammy websites are linking to site B, and at least a significant number are also linking to site C. Google spotted those spammy sites, and devalued their links. So sites B and C lost a lot of the link juice they were getting from those links. That means they have less to pass on to site A. So their links are worth correspondingly less…and site A loses some of its rankings, not because of all the nofollow links, but because links that don’t even connect to it directly got devalued.
Other issues that gazzahk noted in reference to Penguin include changes to the benefit from anchor text, “and it appears there may also have been a significant devaluation of what type of links to and do not bring juice any more. It also appears that there was a significant change to geo relevance around April as well.” If you saw your website’s ranking drop in April, Google’s Penguin update may be to blame.
Not surprisingly, SEO Chat forum member fathom also weighed in on the issue. He noted that “According to Google, any link with the nofollow attribute in the element is categorically dropped from the link graph.” Additionally, “a dozen or so Google staffers have suggested if you have been devalued by PENGUIN you do not need to delete webspam; simply add[ing] the nofollow attribute will undo devaluation while allowing you to keep any referral traffic from ‘paid links,’ ‘traded links,’ ‘link wheels,’ or any other webspam links.”
This is a little different from worrying if nofollow links pointed to your site are hurting you; it’s more a question of managing your outgoing links, and making sure that the ones that get dofollowed are relevant. Google assumes websites can control their outgoing links, after all. Still, simply slapping nofollow on the links in your blog comments might not be enough.
Consider this: a number of spammy comments on your pet-training blog talk about cheap drugs and drop links. You have them nofollowed, so you figure you’re covered and don’t bother to actually clean up the comments. Well, Google crawls that page of your blog, takes a look at the content, and its algorithm gets confused. Is this page about pet training or cheap drugs? Moreover, all those spammy comments might look like keyword stuffing to a computer algorithm.
I’ve barely scratched the surface of this discussion. How do you handle the rel=”nofollow” attribute for your website? What kind of role does it play in your link building campaign? Feel free to answer in the comments below or join the discussion at the thread, linked above.