This is actually a rather common question. It stems from a basic understanding of page rank and how it affects a website’s ability to rank within a search engine.
I suppose the first thing we should actually do, is establish exactly what it means to nofollow a link, and why people may think it is a solid SEO strategy.
Why People Think They Should Nofollow All External Links
Page Rank (fondly referred to as link juice by many SEO’s) is the very first algorithm that Google used to rank websites. It is actually named after Larry Page, one of the founders of Google.
The algorithm works on the theory that the most valuable, or highest quality web page will be the one that has the most links coming to it. As the better it is, the more other webmasters will want to link to it.
Each web page has a ‘score’ based upon how many other pages are linking to it.
This score can then be passed on towards other pages, based upon which pages it then links to.
The diagram above shows a webpage that has PR8 (or 8 Page Rank points), the page then has 4 links coming out of it to other pages. Each link receives an equal amount of juice.
You may note, that I have been talking about pages receiving link juice from a link, not domains themselves.
This is because PageRank is passed from page to page, not from domain to domain.
Any page on your site is almost always going to link more frequently to more pages on your own site than an external site.
The above diagram may actually look like this, where the blue pages are your website, and the black page is an external website.
In this scenario we have ¾ of the link juice passing to another page you own and ¼ of the link juice going to someone else’s website.
As we know, the more link juice on a page, the better chance it has of ranking.
In this scenario, you are helping your own pages rank better for their key terms, as well as helping someone else’s page rank better for its key terms.
In 2005 Google Introduced the rel=”nofollow” tag for links.
This tag instructed search engines to not follow (and therefore not pass the page rank) for any link that was labeled this way.
The measure was brought in to address the wide issue of comment spam (a process in which an SEO places links within comments sections of other pages, in order to glean some page rank for the site they are trying to rank).
It is also now used:
- as a way of marking that a link has been paid for, such as banner advertising links
- as a way of signaling that you do not trust the site you are linking to
This meant that you could apply the nofollow attribute to a link, and stop the page rank from going through that link.
In this scenario, it could be applied this way:
By not sharing any page rank with the external website, it maximized the amount of page rank that would remain on your own site.
By maximizing the page rank on your own site, you stood a better chance of ranking better within the results page of the search engine.
This inevitably led to the following attitude:
Besides the obvious problems interacting with the online world in a similar fashion to Golum, there are also other very strong reasons that this attitude will not help page get higher on the results page.
In June 2009, The Way GoogleBot Treats NoFollow Links Was Changed
In an effort to stop webmasters from PageRank sculpting (essentially having a very direct control of where the juice will flow), there was a small change made with a large ramification.
Rather than simply not passing juice to the links which have the rel=”nofollow” attribute, the PageRank now evaporates for the non-followed links.
The scenario now looks more like this
Suddenly, acting like Golum not only is socially reprehensible, but it is also completely pointless.
Incidentally, this update also means that the common practice of nofollowing internal links on your own site, is not only pointless, but will actually cause harm to your sites ability to rank.
You can have a further look into this announcement from Google (Via Matt Cutts a Google Software engineer) by checking out Matt’s blog here.
Ranking In Google Is Not All About PageRank
It is also worth noting, that there is far more to the algorithm now than simply page rank.
Suffice to say, you should also at least be thinking about TrustRank.
This is a much harder metric to follow however, as it is designed to try and assess (algorithmically) just how trustworthy your website it.
Probably the simplest way that this can be described is to use a similar metaphor that Google has frequently used.
The internet is essentially an online version of the world.
There are individual sites, and these sites exist within a ‘neighborhood’ of websites.
The ‘neighborhood’ is determined by sites that regularly link with one another.
The type of neighborhood that your site exists within is dictated by the link network that your site exists within.
In other words, every site you link to, and receive links from, contributes to how trustworthy your site is.
You can have good neighborhoods, and you can have bad neighborhoods.
Here is a completely over simplified way of showing two possible neighborhoods of websites.
The green websites interact with one another quite a lot, often linking to each other’s content.
Their main goal in existence is to provide value to their visitors, and they only have the best intentions.
The red websites are the untrustworthy websites on the internet, they are mostly trying to achieve dishonest purposes, such as:
-stealing credit card details
-deceptively selling products
-spamming the living daylights out of people
- do I really need to keep going?
The point is, that if you are never letting a search engine know what ‘neighborhood’ you are a part of, then it can never truly understand if your site can be trusted.
The blogger Brian Dean, has a great article that he has put together on TrustRank if you would like to look into the topic even further.
In short, there is absolutely no reason for you to be nofollowing every single external link from your site, in fact there are ample reasons that you absolutely should not be following this ill advised practice!
Author Bio: Joshua Ballard is the founder of Paradox Marketing, an inbound marketing agency in Adelaide Australia. When he isn’t glued to his screens you can find him hunting out the best coffee in his near vicinity, so that he has the energy to get back to those monitors!