A Brief History of Dofollow, Nofollow, and UGC Links  
First of all, the concept of "nofollow" links emerged in 2005 as a collaborative initiative between Google and other major search engines to combat spammy backlinks. Indeed, spammers were exploiting comment sections on websites to build links for SEO, which forced search engines to find a solution. Consequently, the "nofollow" attribute was introduced to signal ... Read more »