SEOs/Webmasters hate Nofollow links. Because it is said that it does not pass a lot of "juice" to our website. But, do you even know its just an HTML tag or attribute value used to instruct search engines bots that hyper-link or a back-link should not influence the link target's ranking in the search engine's index. This are also suspicious links which are still known to pass link juice with a hidden motto. Although not directly. It is just an indication provided for back-links.
It was originated and announced on January 18, 2005 with the collaborations from three major search giants – Google, Yahoo and Microsoft. It was introduced to stop the spam like Blog comments, paid links as back-links are used as a ranking signal. And the main intention behind this attribute was to stop the credit being passed from a linking website to the linked website. As webmasters or website owners does not get ready to share the authority of their sites.
Here's the example code-snippet on how to check
how Nofollow back-link look like:
<a href="abc.com" rel="nofollow">ABC</a>
There is one more type also:
i.e. <a href="abc.com" rel="external nofollow">ABC</a>
Benefits of Nofollow Back-link
Although this links are not renowned from SEO perspective but still they have benefits.
The first and the last should-be intend of back-links. Nofollow back-links helps to increase referral traffic from other website which link you. It results in increasing your audience or user base.
When to give a nofollow link:
1. In Code Embedding
When you're embedding code of other sites or resources from other sites, then you should give a nofollow attribute to that link. It will prevent your domain authority being shared or passed to the linking site.
2. In Blog Comments
If your website have a blog and you are allowing comments then you can probably give nofollow attribute to those comment links.
3. Untrusted Content
Give it a nofollow if you do not trust it.
4. Crawl Prioritization
In one way you are also prioritizing the crawling density of your web-pages. If you give it a nofollow then automatically other contents of your web-page will be prioritized by web robots.
It also gives signal to Google or any other search engines that you're building your links naturally and do not intend to spam. This also indicates that you're interested in building natural links which can increase your user base or traffic. So, keep in mind that “nofollow links” are not the end of the world :)