If you have any experience with digital marketing, chances are that you’ve probably heard the term “link building” before, but what is it exactly? And why is it such a big deal in the world of search engine optimization? To answer this question, we’ll first have to examine what search engines use links for.

How do search engines use links?

There are two fundamental ways that the search engines use links:

1.     To discover new web pages

2.     To help determine how well a page should rank in their search results

Search engines keep their webpage indexes up to date by regularly sending search engine crawlers, also known as bots or spiders, to visit and gather information from websites across the internet. Once a crawler enters a given webpage it extracts all of the content found on the page in order to determine if it is of sufficient quality to rank for any relevant search queries (keywords). When making this determination search engines do not only look at the content of the page, but also at the number of links pointing to the page from other sites and the quality of these other sites. Generally speaking, the more high-quality websites that link to you, the more likely you are to rank well in search results.

What is link building?

Link building is using a variety of methods to acquire hyperlinks to your website from other websites with the ultimate goal of improving your site’s search engine visibility. In this context, links are often called “backlinks” since they link from an external web property back to your own.

Why is link building important?

Link building is important because it is a major factor in how Google and other search engines rank web pages. In Google’s own words:

“In general, webmasters can improve the rank of their sites by increasing the number of high-quality sites that link to their pages.”

It makes sense that increasing the number of quality links to your site results in improved rankings. Think about it: if another site trusts you enough to send you their users, it’s a pretty good indication to Google that they should increase their trust in your site as well.

Link Value Signals Used by Google

Like I mentioned previously, search engines use links for two reasons: to discover new web pages and to determine how well a given page should rank in the search engine results page. This begs the question, which specific factors do search engines look at to make this determination? The answer to this question will be different for each search engine. For Google, the list of known link value signals is as follows:

Authority of the Page (PageRank)

This is the most important factor when it comes to link value. Formerly known as PageRank, this concept is still a core component of Google’s ranking algorithm. Put simply, the more authoritative a page is perceived to be by Google, the more authority it will pass to your site through a given link. PageRank information isn’t shared publicly for multiple reasons, but a good proxy indicator is Ahrefs’ URL Rating (UR).

Authority of the Site

A link’s quality is also influenced by the authority of the domain it links from. For example, a link from a site like NYTimes.com or cdc.gov will have a more significant impact than a link from a site no one has ever heard of. Similar to page authority, Ahrefs’ Domain Rating (DR) is a good proxy indicator you can use to determine a site’s overall authority.

Relevancy of the Site

Another important value signal used by Google is site relevance. For the sake of example, let’s say you run a website about motorcycles and you earn a link from an authoritative site about baking like foodnetwork.com. Will this link still be valuable to your site? Sure, it will pass some value or “link juice” to your site, but not nearly as much as a link from an authoritative site closely related to your niche would, like harley-davidson.com for instance.

Link’s Position on the Page

Links placed in the footers and sidebars of a page, or in the navigation bar of a site, are not worth as much as links found within a page’s body content.

Is the Link Editorially Placed?

In other words, was the link naturally placed by the someone with editorial jurisdiction on the site, e.g., the site owner, an admin, a reporter, etc., or was the link placed unnaturally? This could mean a variety of things, an unnatural link could be one that you posted in a comment after creating an account on a site, or a link that you negotiated the placement of through some sort of exchange—be it monetary, quid pro quo, or otherwise. Google does not weigh unnatural links nearly as heavily as it does editorially placed links, and they may ignore, or even penalize you for them (as link schemes violate their Webmaster’s Guidelines).

Link Anchor Text

Anchor text, the clickable text component of a hyperlink, is a major signal Google utilizes to determine link value and relevancy. In keeping with the previous example, let’s say someone links to a page on your motorcycle website by placing a link in their blog with the anchor text: “motorcycle brands.” This indicates to Google that the page being linked to is probably about different motorcycle brands and will likely help your page rank better for related search queries.

Google treats anchor text very similarly to the way they treat editorial vs unnatural links, meaning that anchor text that is deemed to be spammy (usually this means you’ve built a lot of links with the exact same, keyword-rich anchor text) will likely be ignored or even penalized. Also, generally speaking, if multiple links on a page are pointing to the same location Google is only going to take in to account the anchor text of whichever link comes first in the HTML of the page, although all of the links will still pass link value.

Link Co-Occurrences

Co-Occurrences, sometimes called “baby anchor text,” are the words and phrases that appear around your link. This text offers Google additional context in determining what the page being linked to is about, especially if the anchor text itself is ambiguous. To illustrate this, let’s say someone links to the aforementioned brands page on your motorcycle site from their blog using the anchor text: “bike brands.” Just based on this anchor text alone Google may interpret “bike” to mean bicycles and not motorcycles, but the presence of the word “Harley” earlier in the blog post will help Google figure out that in this context “bike” means motorcycle, not bicycle.

Nofollow vs Dofollow Links

rel=”nofollow,” rel=”ugc,” and rel=”sponsored” are tags added to the HTML markup surrounding a link that indicate to Google that you are not endorsing the link for various reasons. Utilizing one of these tags means that no link value will be transferred from the linking page to the linked page, and Google will not crawl the link, although it may find and index this page through other means, i.e., an XML sitemap, a link to the page somewhere else on your website that does not use these attributes, a link to the page from a different site, etc.

Now, you hopefully have a better understanding of what link building is and what some of the ways Google determines link value are, but you may be asking yourself: “Okay. What’s next?” Good question! The logical next step is for you to start identifying link building opportunities – but how are you supposed to know the difference between a “good” and “bad” link? Another good question! You can read more about understanding link building opportunities here, or reach out to us for a conversation using the form below.