Nofollow is introduced by Google’s webspam team Matt Cutts and Jason Shellen from Blogger.com in 2005. They also manage to convince other major content management players like WordPress to make their comment section to nofollow in default. This will give rel=”nofollow” tag to the commentators link in any blogger.com or wordpress hosted blogs by default. Google will not use any link with rel=”nofollow” tags attached in their ranking system. Meaning, backlinks with nofollow tags will not help you increase page rank or increase SERP ranking in Google search engine.
The main reason nofollow tag introduced is to control commenting spam in 2005. However, many webmasters tend to misunderstand the concept of nofollow link and goes extreme by having nofollow links on each link goes out from the blog or website. Some even gives nofollow links to all internal pages from the website or blog. Nofollow link is meant to control spamming. So, your content section can avoid using nofollow links because nobody has access to post or edit contents section with spammy links. All your internal pages should avoid the use of nofollow links. We want our internal pages to get page rank juice and rank well in SERP ranking.
Give nofollow link to sites that are not relevant to your niche. You don’t want Google to give credit or penalize your to give a link to bad neighborhood sites like adult, gambling, pharma or etc from your website. If can’t avoid giving the link to bad neighborhood site (credit links in footer from free templates), you need to make it nofollow. Alternatively, you can also remove footer links by asking permission from template owners. Give nofollow link to pages where contains many outgoing links like comment section and forums. If you have the time and resources to check each outgoing link (to determine whether it is bad neighborhood), then you can give dofollow link. If not, I would suggest using nofollow link.
We can’t say that nofollow links are totally not useful interms of SEO. Only Google and Bing does give ranking factor benefits to nofollow links. Other search engine like Yahoo still gives credit to nofollow links in their SERP ranking. Search industry also works mainly on contents. Contents delivered by commentators will be indexed and able to attract traffic from search engines with unique keyword searches. Some search engine experts have claimed that almost 70% of searches made in Google are unique and long tail keywords search. So, the short content delivered in comment section will still benefit the blogger.
Having nofollow links from your link building campaign will make your backlinks profile looks natural in Google’s view. Taking note that Google don’t motivate us to do link building at our own as they prefer to backlinks from organic type. Obviously, not many have the patience to wait for good organic backlinks especially if the website is new. So, we must make our link building campaign look natural with a mixture of nofollow and dofollow links. Getting only dofollow links may make us look bad. Getting only nofollow links will not help in SEO in Google. But, having both nofollow and dofollow back links will make us look extremely natural. Now, you will have a better opinion of nofollow link value in SEO.