Website backlinks, otherwise known as incoming links, are one of the most important and valuable assets in your SEO toolbox.
Backlinks are also one of the most misused and abused forms of SEO, leading to Google’s constant war against Internet spam and unscrupulous SEO companies trying to make a quick buck off unsuspecting website owners.
Website Backlinks Are The Currency Of Off-Site SEO
We can consider website backlinks as the basic currency of our overall SEO value on the web and, at its simplest level, we can think of PageRank as the numerical equivalent of that currency.
In recent years, PageRank has become far less important in Google’s eyes, but we can still use it as a guide to understanding the relative importance of pages.
PageRank is expressed as a number on a scale from 0 – 10 and, although no one outside of Google fully understands how it’s calculated (or even what the scale means exactly), it can be thought of as being logarithmic in nature.
This means it might be 2 times (or more) harder to move up from a PageRank of 1 to a PageRank of 2, and 2 times more difficult again to go from a 2 to a 3, and so on.
All new websites start with a PageRank of 0 and then move slowly up the scale as time goes by and they gradually gain authority with Google.
The authority (its importance in Google’s eyes) of a web page is derived from many factors, including the number and quality of the backlinks pointing to it.
Essentially, when one website links to another, Google looks at it as a “vote” for the website being linked to, and a certain fraction of the linking website’s PageRank (often called “link juice”) is donated to the target website.
Not All Website Backlinks Are Created Equal
However, it doesn’t take long when dealing with SEO to realize that not all links are created equally, and some backlinks are worth a great deal more in terms of link juice than others.
In short, a backlink from a trusted domain with a high PageRank is worth much more than a link from a website with a lower PageRank, and will therefore help a lot more with your search engine rankings.
The problem for the photographer comes when trying to attract links from high-ranking websites, as they can be difficult to get.
You can see a stylized graphical example of this effect in action in the diagram below:
In this example, let’s assume your website has a PageRank (PR) of 2, and you can see the backlinks coming in from a range of other websites, all with varying PageRank values.
As you can see, it takes a lot more backlinks from lower-ranked websites to have the same effect on your search engine ranking than it does from a single, higher-ranked website.
Obviously, the diagram has been simplified greatly to communicate the concept and, in reality, these effects may be greatly increased. There are many other factors to consider (such as how many outbound links the donating website has), and it might take many hundreds of links from lower-ranked websites to match the power of a backlink from a highly trusted site.
There’s also one class of backlink that we should mention here for clarity and completeness, which is the reciprocal link.
A reciprocal link simply means what its name suggests – a mutual exchange of website backlinks.
On the face of it, you might expect that the net PageRank exchange between the two sites is zero, since website A passes link juice to website B, which is then donated back again via the reciprocal link, however that’s not necessarily the case.
The amount of PageRank donated from one website to another is heavily dependent upon how many other websites each page links to. If you think of each page as having a finite amount of link juice to give away, then it can’t donate more than it’s worth, so the donated amounts are shared equally between the outgoing backlinks.
This frequently leads to situations where the reciprocal link isn’t really reciprocal in the amount of link juice that’s exchanged.
For example, consider the scenario detailed in the diagram below.
In this situation, you’re donating a higher percentage of your link juice to website “B” than you’re receiving because website “B” must share its outgoing link juice donations between a higher number of websites.
There’s also been talk from Google that reciprocal links that exist purely for their own sake are being devalued, since they resemble link schemes and manipulative SEO techniques.
So, when another website suggests a backlink exchange with you, be aware of the potential downside if the other site is a larger, more trusted website with a large number of outgoing link, or the link is simply a trade of links with no real purpose of sharing valuable content.
However, you shouldn’t automatically reject the offer – after all, a link is a link, and its value can’t be measured solely by the amount of link juice it shares with you. There are other factors to consider, such as the potential for increased visitor traffic in the form of referrals.
Followed vs. No Followed Links
The story of backlinks would not be complete without a short discussion of the difference between “follow” and “nofollow” links.
This concept came about shortly after the explosive growth of blogs, where visitors could leave comments on the articles and posts they’d read. Commenting usually involves leaving a name, email address, the comment text, and (like a pot of gold sitting under the rainbow) a website backlink.
The original intention was to reward those who took the time to interact with the blog with a backlink to their website. It seemed like a fair exchange but, of course, this was seen as a great opportunity by Internet spammers to leave comments everywhere they possibly could, with multitudes of backlinks then pointing back to their spam-laden websites.
Google and the blogging world quickly responded to this with the introduction of the “nofollow” attribute on outgoing links, and almost all commenting systems now use it.
In HTML language, it looks a bit like this:
<a href=”some destination link” rel=”nofollow”>Anchor Text</a>
For the record, rel=”follow” is the implied default if the “rel” attribute is not specified.
So, whenever the search engine spiders encounter a “nofollow” link, they might record the existence of the backlink in the index, but no link juice is actually given to the target website. To all intents and purposes, it’s as though the link wasn’t there.