Nofollow tags are frequently misunderstood. In this article we look at nofollow tags, their rationale, and how to nofollow (or “dofollow”) links on WordPress.
Google’s success as a search engine was largely based on its founders’ development of an algorithm that used incoming links as a signal of a page’s quality. The idea is that the more people who choose to link to a page, the more valuable the page is likely to be to other people. Although Google and the other search engine operators have increased the complexity of their algorithms considerably since the early days, links still play a fundamental role in determining search engine ranking.
However, not all links are trustworthy for the purposes of determining a page’s quality and value. They are only useful if they are “editorial” links — links that are created because the value of the content is what motivated the link. Because there are various other reasons that a page might be linked to, Google decided to provide a mechanism to signal that links should not be followed by search engine crawlers. That mechanism is the nofollow meta tag, which looks like this:
Google specifies in its Webmaster Guidelines that some types of links should use the nofollow tag. Google also uses nofollow tags, particularly in advertising.
The most important class of links that Google prefers to be nofollowed are links that have been paid for. What counts as payment isn’t straightforward, but if there is some exchange of value between the linker and the target, it’s worth thinking about using nofollow tags. The paradigmatic example of paid links is straightforward: Site A gives Site B some money; Site B puts a link on their page leading to Site A. Links in paid advertising also count, as do links in native advertising.
The reason is not hard to grasp. Google wants to count earned links. Its indexes would be detrimentally affected if sites could simply buy their way to the top of the SERPs. If Google catches a site selling links, then it’s likely that site will be penalized in the SERPs.
Buying links is not the only way that bad SEOs try to increase the ranking of their sites with link building. Comment spamming, forum spamming, and various other malign practices are also popular. Link spamming can be a big problem for sites that include user-generated content, including WordPress comments. That’s why WordPress includes nofollow tags on all links in comments by default — it’s a waste of time to link spam sites when it has no impact on search results.
Links can be seen as an endorsement of the target page; that’s why they’re valuable for search engines in the first place. But, on occasion, site owners would like to link to a page without the implicit endorsement. Using nofollow tags on links allows writers and webmasters to point readers in the direction of a page without endorsing it or passing along “link juice”.
Nofollow In WordPress
As I already said, user generated content is nofollowed by default in WordPress. That’s generally the smart choice, but some bloggers and site owners prefer to allow the links their users contribute to pass PageRank. Also, it can be useful to have more control over which links in a site’s content are given a nofollow tag: to avoid the appearance of selling links, for example. The Ultimate Nofollow WordPress plugin allows WordPress users to take complete control over which of their links include the nofollow tag.