Link building just might be the most misunderstood aspect of SEO.

Any experienced digital marketer knows that links play a role in Google’s evaluation of a site. But how exactly does Google’s algorithm use links when determining a site’s authority? Are backlinks received from press releases or social mentions helpful for SEO? Are multiple links from the same site equally impactful? And most importantly, where should a marketer start when it comes to building backlinks?

In this article, I’ll lay a foundation for understanding the history of backlinks, answer a myriad of FAQs about backlinks, and ultimately touch on the benefits of backlinks when it comes to a site’s organic, “earned” visibility in search engines.

But first, let’s take a look at the anatomy of a backlink.


What is a Backlink?


There’s more to a backlink than meets the eye.

Behind the scenes, there are 4 different elements that make up a backlink:

  1. Start of a Link Tag
  2. Destination URL
  3. Anchor Text
  4. End of Link Tag


While some components of a backlink – like the start and end of a link tag – are fairly self-explanatory, others are more complicated.

Destination URL refers to the page that users are sent to after clicking on a link. In the example above, is the destination URL of the link. It’s worth noting, however, that a link’s destination URL isn’t visible while browsing through a site or reading content. In order to access the source code of the link and view a link’s destination URL, highlight a link, right click, and choose ‘Inspect’.

Anchor text is the word or words that make up the visible link on a page. Anchor text is often stylized in a color that varies from standard text, and is underlined and/or bolded to stand out from standard copy. Anchor text serves as a simple way to communicate the page contents of a link’s destination URL for users, but it also serves an important purpose when it comes to SEO.

Just as links allow users to navigate from page to page on site, they also help search engine bots or “spiders” to discover new pages and, ultimately, decide how to rank those pages for specific keywords. Anchor text then is critical for search engines because it communicates which keyword themes should be “owned” by a link’s destination URL. If a search engine spider crawls a link with non-descriptive anchor text, there’s still a strong likelihood that it will discover the content of the link’s destination URL, but if the same link utilized a descriptive anchor text, the power of the destination URL’s content is magnified, and the page’s ability to rank well in search results is improved.


Why are Backlinks Important? A Brief History


On one hand, Google has been candid about the fact that backlinks are everything. On the other hand, it’s very clear that acquiring backlinks without an understanding of how search engines view links or a strategy to ensure you’re getting the right kind of links is putting the cart before the horse.

So why are backlinks so damn important? The simple answer is that each backlink represents a vote of confidence about a page. Thus, measuring a site’s backlink portfolio is a method of measuring how frequently others consider it to be authoritative – or at the very least, authoritative enough to be referenced. The thinking follows that when someone links to a site, they are essentially saying the site is a good resource and should be rewarded as such within search rankings.

But that’s the short answer…

Google began its rise to dominance in the search engine market in the late 1990s when one of Google’s founders, Larry Page, invented PageRank, which Google used to measure the quality of a page based in part on the number of links pointing to it. As PageRank was added to the overall ranking algorithm, it became more clear that inspecting a site’s link profile was an effective method of determining it’s quality.

Why was PageRank such a breakthrough? Until PageRank was rolled out, Google’s algorithm more or less equated backlinks (of any kind) with authority. And while this was a step in the right direction, it didn’t take into account the quality of the link’s domain, the location of the link within a page’s content, or the reason why the link had been given in the first place. This lead to an algorithm that was too simplistic to accurately judge whether a site was truly authoritative and valuable for searchers, or whether a site’s owner had simply gamed the system and been rewarded with rankings.

At that point, Google’s webspam team began actively working to uncover websites that were manipulating search results, and began rolling out regular updates to its algorithm which were specifically aimed at filtering out websites that didn’t deserve to rank. If you’re interested in learning more about what Google currently considers low quality, ineffective, spammy link building, this is a great resource.

In the past few years, Google has gone a step farther, penalizing sites who have overused link building techniques – such as using keyword-specific anchor texts in every link to a page – and therefore, “over-optimized” their site. Google’s Penguin updates are one such example.


Backlinks vs. Referring Domains


Back in 2016, Google publicly shared that apart from content itself – specifically, written copy that can easily be crawled, categorized, and indexed by search engine spiders – backlinks are the most heavily weighted ranking factor. In short, if you want a site with true organic visibility and authority (the kind that leads to traffic and conversions), you need backlinks. If only it were that simple…

A  Google engineer would agree that it’s an understatement to say that Google’s algorithm is complex. Nonetheless, we know that Google’s algorithm utilizes backlinks in a very specific way when determining rankings. Google views a site’s referring domains as a major indication of whether or not a site’s content itself is valuable and worth prioritizing a sin search results.

Once search engine spiders have successfully crawled your site, they automatically extract the content of your pages and add it to their index. For those of us that are readers, it can be helpful to think of Google’s index like the largest library in the world – full of information of every kind, ordered systematically so that any piece of information can be accessed in a moment’s notice. Once a site is entered into the index, Google can decide whether or not they feel a page offers enough value to be ranked well for relevant keywords.

But it isn’t merely the number of backlinks pointing to a site that Google evaluates when determining rankings. In order to prevent spammy sites from gaming the system by building large amounts of links via a single site, known as a “link farm”, the algorithm was updated to go a step further and evaluate the number of unique domains that refer to a site as well. In doing so, Google devalues all backlinks acquired by a single domain after the very first link; even more, Google’s webspam team considers this kind of link building unnatural and isn’t afraid to hand out manual penalties to sites that don’t follow Google Webmaster Guidelines.


Thus, it’s not merely the quantity of backlinks, but also the quantity of unique referring domains pointing to a site that determines where it will rank organically. It’s often useful to think of backlinks coming from unique referring domains as votes of popularity for a particular site. The more votes received from trusted voters, the more likely a site is to receive visibility in Google searches. But remember: the value of every vote after the first is discounted accordingly.

Note: It would be foolish not to reference the quality of the referring domain and the backlink itself here. As you can probably already guess, quality means everything when it comes to effective, white hat link building. To get a pulse on where metrics like Domain Authority, Page Authority, and Spam Score come into play, continue on to FAQs about backlinks below.


Before You Get Started


With every algorithm update comes a slew of new methods promising to optimize sites and bring page 1 rankings overnight. In reality, any offense to Google’s Webmaster Guidelines poses a threat to your site’s current rankings and long-term SEO health.

But if we zoom out just enough to see the current SEO landscape, one thing is certain: Google loves quality. Thus, link building should be pursued as a way of enhancing the reputation of a business with content that is already valuable in and of itself. Put another way, “Any campaign that starts with ‘getting links’ as the objective, without placing primary and ongoing focus on the quality and focus of the content being linked to, will eventually run into problems.”

The fact of the matter is that once you have an amazing product and incredible on-page content to go with it, acquiring links to that content will not only be more doable, but also more effective.