A nofollow link is a link that contains a rel=”nofollow” attribute in its HTML code. This attribute tells search engines not to pass authority from the linking page to the destination page. As such, noffollow links have very little value from the SEO point of view.
The nofollow attribute was introduced in 2005 by Google, Yahoo and MSN in order to fight the comment spam by giving webmasters the option to devalue certain links.
Nofollow vs. dofollow
From the technical point of view, the only difference between a nofollow link and a standard “dofollow” link is the presence of the rel=”nofollow” tag. The practical difference is that nofollow links do not pass the link equity (also known as “link juice”). In other words, if you get a nofollow backlink, the linking page doesn’t pass the authority to your page. It won’t improve your rankings and transfer any PageRank.
When should I use nofollow links?
1. Pages you don’t want to endorse
Sometimes you simply need to link to websites that you don’t want to endorse.
For example, here’s an article by the Variety Magazine reporting on Pornhub releasing a non-adult film. Although all the links in that article are followed, they decided to use a nofollow attribute when linking to PornHub’s annual review.
2. Sponsored links
Buying links is an activity that is strictly prohibited by Google’s guidelines.
So you don’t want to be caught by Google on the receiving end of the link, but neither should you be obviously selling links on your website.
The only way is to use a nofollow attribute on all the sponsored links, more precisely rel=”sponsored” (rel=”nofollow” will work the same way, or you can combine both values like rel=”sponsored nofollow”).
3. Affiliate links
This is very similar to the previous point. Although affiliate links are not “sponsored links” per se, it is best practice to nofollow them.
4. User-generated content
Any time a visitor is able to insert a link on your website (in most cases it’s the comments or forum posts) it should be automatically nofollowed.
Do nofollow links have any SEO value?
There’s always been a lively debate about the possible impact of nofollow links on rankings.
Has a nofollow link from a relevant Forbes article really the same SEO value as a nofollow link from a spammy comment on a random website?
We don’t know. But even if nofollow links pass no link equity at all, there are other indirect benefits they bring.
1) They may serve as a hint for Google
What does it mean?
Well, nobody knows exactly. One of the possible interpretations is that Google may decide to “ignore” the nofollow attribute in some cases. It may be for the ranking purposes or just for crawling and indexing.
But more probably, they’ll just use them internally to help them improve their understanding of links and the content of the linked pages. After all, their official statement is that these hints will be used as “a way to better understand how to appropriately analyze and use links”.
2) They can bring you traffic
Remember the example with a nofollow link from a relevant Forbes article and a nofollow link from a spammy comment?
Even if there was no difference from the “PageRank” point of view, there’s definitely a difference in the traffic potential these two links have.