In theory, the search engines don’t follow links with the NoFollow attribute attached. That’s what NoFollow means. However, anybody who has been checking backlinks for multiple websites (for example, if you have many SEO clients, prospective SEO clients, competitor websites, etc.) will notice that Yahoo lists many NoFollow links as backlinks (I wrote about this last year, too.). I have seen this at Google (I believe in Webmaster Tools, but my memory is not certain on this point – sorry).
If the search engines index NoFollow links, it is possible they use the data (otherwise, why waste so much computing resources indexing them?), despite that purpose of the NoFollow attribute being that the links should not count in their algorithms. This post speculates on how the search engines might use this data.
A Partial History of NoFollow
Seasoned SEO experts can skip this section. It is intended for newbies, and it is only partial because I am sure I am missing out some details.
Before there were blogs, there were guest books. Guest books were like prehistoric Web 2.0 . They allowed website owners to create some form of user interaction with otherwise pamphlet-like websites. They engaged the user. They created stickiness. Best of all, they were set-it-and-forget-it, so many website owners thought “why not?”
Spammers quickly learned that they could drop links in guest books, which were often unmonitored. The extent to which this was happening reached near epidemic proportions to the extent that serious SEO specialists were leery of leaving any links in guest books for fear of having their websites penalized for spamming. Search engines were concerned because any mass linking scheme threatens to skew the quality of the search results they present their clientele – the searchers.
The search engines were let off the hook by the website owners. Those who did not moderate their guest books were disgusted by the spam. Those who did moderate their guest books were frustrated by the spam. For a low- or no-maintenance tool, guest books were proving to be a pain without any obvious benefit (such as increase in sales).
In truth, blogs came along and offered a much better way to engage visitors in a two-way conversation. Blogs offered a venue for opinionated and chatty webmasters to engage with visitors, and the blog CMS was much easier to handle than an “articles” section on the website (especially because many bloggers found they could dispense with pesky technicalities like grammar and even staying on-topic.). Blogs also offered a much more obvious business benefit than guest books – search engine rankings, which could be translated into increased sales.
It wasn’t long before blog comment spam had replaced guest book spam. But this time, the search engines would not be let off the hook. Blogs had so many obvious benefits and so much more invested in them that, instead of petering out, they kept proliferating. Indeed, each blog spawns hundreds or even thousands of pages, each one fertile for dropping a spammy link in a comment. And many blog owners were (and still are) lazy, allowing comments to be automatically posted without moderation. NOTE: This blog is moderated, and I use a DoFollow plugin. If your comment is worthwhile, your link will count. If your comment is not worthwhile, sorry.
Many bloggers became alarmed at all the spammy links, and were worried that they might be penalized for linking to bad neighborhoods. That’s why the search engines created the NoFollow attribute. And if you believe that, I have some superb oceanfront property on the moon that might interest you for a surprisingly reasonable price.
In fact, search engines were once again concerned because as I said earlier any mass linking scheme threatens to skew the quality of the search results they present their clientele – the searchers – and mass automatedblog comment spam was showing no sign of slowing down.
The search engines gave everybody, not just bloggers, a simple means to indicate when an outbound link from their website should not be followed by the search engines because it is not a link in which they have placed trust. Basically, the whole point of NoFollow is to eliminate user-generated links from the algorithms, since those links cannot be considered as “votes” for the sites being linked to by the sites doing the linking.
So Why Are Search Engines Indexing NoFollow Links?
This is a puzzle. If the search engines created NoFollow to tell their robots not to follow, obviously something has changed since then, because they are following. But do the links affect the rankings? Here are a few theories of how the search engines might be using the data. These are highly speculative, so feel free to throw in your own speculations into the comments below.
- One obvious theory is that the search engines are not using this data at all in their rankings.
- A second theory is that the search engines are using the links to determine relevancy (a link from a comment on an SEO blog to my website helps the search engines confirm that my website is about SEO), but that the links do not count toward link popularity or PageRank.
- A third theory is that the search engines have built into their algorithms a process for selecting which NoFollow links they should include in their algorithm calculations. For instance, they might choose to follow all Wikipedia NoFollow links, but no MySpace NoFollow links.
- A fourth theory is that the search engines use NoFollow external links to dampen their trust rating of a website. If a website owner has lots of external links that it is not willing to trust, that is one signal that the linking website itself is not all that trustworthy. Makes sense for MySpace. Bummer for Wikipedia (but I’ve voiced my opinion on Wikipedia’s abuse of the NoFollow attribute before).
- A fifth theory is that the search engines use NoFollow internal links to dampen their trust rating of a website. Unlike some of these theories, this one makes sense. After briefly experimenting with internal NoFollow internal links on one of my websites, I removed them all. Think what message it sends the search engines about the quality of your website if you say you can’t trust your own web pages.
- A sixth theory is that search engines do not use NoFollow links directly in their rankings, but that they are included somehow in a link profile establishing a website’s level of activity on the Web.
I would like to hear your comments and theories. I should note that I have not researched this post in any great deal, because it really is just speculation. I wrote it while my daughters danced last weekend, and there is no WiFi there. So feel free to add your theories and enlighten me and our readers if you know of any great sources that can shed some light on this.
You can easily tweet this post by clicking Retweet ThisWritten by David Leonhardt
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