Why Implement NoFollow Links?
1. The popular search engine optimization nofollow HTML attribute is the solution to what many believed to be a huge problem in the blogging community. In early 2005, Google’s Matt Cutts and blogger Jason Shellen designed the rel=“nofollow” attribute to assume the responsibility of stopping spammy blog comments made primarily to boost the link popularity of the person leaving the comment.
Here’s how it works: by adding rel=“nofollow” to a hyperlink, a page signals that the hyperlink’s destination should not be ranked by search engines. The search engines see the nofollow tag in an HTML link but do not follow it, nor do they allocate link popularity to the destination page. Though many squabble about its effectiveness at stopping comment spam, the idea is that spammers will stop posting if the search engines stop giving page ranking credit.