\nThe following is by my understanding.<\/p>\n
\n(Herein, the opposite of a nofollow link is referred to as an ordinary link.)<\/p>\n
\nMost people likely have heard it’s links to a site that determine where that site is presented in search. That’s probably an oversimplification, but substantially correct. For precision, some will argue that not all links are worth the same: links from an “authoritative” website (whatever that means) count for more than ones from a less regarded one. Moreover, “nofollow” links are meant not to count – meaning they don’t improve the site’s search position that they point to. Only ordinary links are meant to help a site in search. While the exact calculation, based on authority as well as ordinary vs nofollow, might be opague, most people seem to agree that if a lot of “famous” websites have links to a certain other one, then that certain other one will likely be near the top in relevant searches.<\/p>\n
\nA nofollow link is one that contains the parameter rel=”nofollow”. In theory, it tells a search engine that said link, while it leads to a given site, shouldn’t improve that site’s position in search. In a link-based system for deciding where a site ends up in search, the concept of a nofollow link might seem bizarre. Yet, there are reasons for it. Said reasons, to me, are somewhat questionable and ironic, so I’ll just say this: rel=”nofollow” is meant to be put on paid links and also on ones to “lower-quality” sites. Now, why someone would want to link to a site they think is lower-quality might seem an obvious question, and it’s left to the reader.<\/p>\n
\nOne reason for the nofollow attribute is that some bulletin boards get spammed with comments filled with links completely unrelated to the topic being discussed. I’d suggest just not publishing those comments, rather than publishing them but changing the links to nofollow.<\/p>\n
\nThe issue of one site being authoritative compared to another has always raised questions to me. Sometimes, the best advice is from an obscure individual; I’ve seen that happen.<\/p>\n
\nAnyway, the actual effect of nofollow seems dubious: nofollow links still appear to help the websites they point to. How much less that is compared to ordinary links is perhaps hard to fathom.<\/p>\n
\nInteresting, eh?<\/p>\n
Source:<\/p>\n
mailchip.com: “The Role of Nofollow Links in SEO”<\/a><\/p>\n