What do you need to know about nofollow?
There is an attribute that can sometimes be applied to links called the “nofollow” attribute. If added, you will not notice any difference if you’re a user. But, if you look at the code of the link, it will look slightly different:
Note the addition of rel=”nofollow”. This tells Google not to pass any PageRank across this link to the target URL. Effectively, you’re telling Google not to trust this link and to discount it from consideration. Therefore, it should not help the target URL to rank any better.
The main reason a site might use nofollow relates to scenarios in which that site lacks total control over the links that are added to its pages. In other words, they don’t want to show Google a vote of confidence when they don’t know whether or not they actually are confident. This is more common than you’d expect; here are a few examples:
Guest book comments
Editable Wiki pages (e.g. Wikipedia)
Guest post signatures
Users can freely add links to each of these places, and because of their size, it isn’t really practical to moderate every single one of those links. So, in order to deter link spammers from taking advantage of a site’s PageRank, the site will often choose to apply the nofollow attribute to all links posted by other users.
Another use for the nofollow attribute is for advertisers to use on links that have been paid for. So, if you buy an advertising banner on a website that links to you, Google says that the nofollow attribute should be added so that they know not to pass any PageRank across that link. The idea here is that you shouldn’t benefit from the organic results by buying advertisements that include links on other websites.
More recently, Google has expanded this concept to included optimized links in press releases, article directories, and advertorials. These are all examples where the use of nofollow is entirely appropriate.
In terms of your work, you should know that links that have the nofollow attribute applied will probably not help your organic search rankings as directly as followed links. That isn’t to say they’re not worthwhile. After all, typical users don’t notice whether a link is nofollowed or not, and may actually click through and visit your website even if it is. That is, after all, the point of buying advertisements online. That being said, for the purposes of link building, you want most of your links to be followed and therefore counted by Google. Looking for a way to identify followed versus nofollowed links on a website? You can use the MozBar to highlight these links on any site.