No-Follow Links

What are Nofollow Links?

These are links with a rel=”nofollow” HTML tag applied to them. This tells search engines to ignore the link.

The only real difference between a no-follow and a do-follow, or follow, link is the rel=”nofollow”.

Typically, according to Google, they don’t follow the no-follow links. Makes sense right?  What this means is that Google doesn’t transfer PageRank or anchor text across the links. The target page may still appear in the Google index if there are other links not using nofollow, or if the page is submitted to Google in a Sitemap.

When to Use Nofollow Links

Here are three examples of reasons to use nofollow links according to Google:

1. Untrusted content: If you don’t want to vouch for content of pages you link to from your site. This is mainly useful for comment or guestbook entries where people post spammy links. If you do decide to add a nofollow attribute to the  the comment section, consider manually removing the attribute from trustworthy contributors.
2. Paid links: In order to prevent paid links from influencing search results and negatively impacting users, Google urges webmasters to use nofollow on such links.
3. Crawl prioritization: Search engine robots can’t sign in or register as a member on your forum, so there’s no reason to invite Googlebot to follow “register here” or “sign in” links. Using nofollow links enables Googlebot to crawl other pages you’d prefer to see in Google’s index. However, this may not be worthy of your time.

Do Nofollow Links Help With SEO?

So there is some argument about this, but it appears that Google does actually follow the links and they do have an impact on SEO, especially if those links are from related sites. The main benefits are:

• improved SEO
• potential traffic from the link
• nofollow links from a popular site can lead to many dofollow links
• and nofollow links are part of a natural link profile

So yes, nofollow links almost certainly have an impact on SEO. It may not be a large an impact as dofollow links, but even that is up to debate.

Additional Sources:
What is a Nofollow Link? Here’s a Simple Plain English Answer
Google Help Center on Nofollow Links
Follow Links Vs. Nofollow Links: Should You Care?