Inbound links are one of the most powerful assets in the world of online marketing. Every link pointing to your website passes authority to your site, making it more authoritative and trustworthy in Google’s eyes. The higher your website’s perceived authority, the higher it’s going to rank in searches, which means more traffic and brand visibility.
Thankfully, Google has safeguards in place to ensure that all links aren’t treated equally; that’s a good thing because it means you can’t spam links across the web to manipulate rankings without getting a Google penalty. Most of us can judge quickly whether a link is “natural” or whether it’s spam, but Google’s evaluation process is more nuanced than this.
So how, exactly, does Google evaluate links in its ranking algorithm? There are seven main factors:
1. Source Authority
As a general rule, the more authoritative the linking source domain is, the more authority the link is going to pass to the site it links to. For example, if a newly created site doesn’t have many readers and doesn’t have many links on its own, it’s going to be a low-authority site; any link you get from it will have marginal benefit at best.
But if you can get a link from an established, well-known online publication, such as The Huffington Post, you’ll get far more benefit from the link. Obviously, the more authoritative the link, the harder it is to acquire, so you’ll need to balance your efforts between those which are most rewarding and those that are actually available to you.
There is a specific exception to the authority rule: the nofollow tag. Google allows you to tag certain links in the HTML code with “rel=nofollow” to indicate that they shouldn’t be crawled, followed, or used as a means of passing authority.
It’s mostly used by publishers to ensure that their authority isn’t damaged by outbound links that lead to questionable sources; after all, links are something of a two-way street. You can also mark your own links with a nofollow tag if you want the link to exist without passing authority to other pages.
It’s commonly thought that if a link is marked with a nofollow tag, Google will ignore it. However, various studies have suggested that nofollow links aren’t always ignored by Google, and that having enough nofollow links may actually be crucial for good SEO.
3. Source Relevance
There’s also evidence to suggest that the relevance of your linking source also matters in Google’s evaluation. If you’re posting on a blog about making great hamburgers, and you link to a criminal defense lawyer’s page, there’d better be a good reason for it. If you’re linking to a site about how to source the best ingredients for your restaurant, it might make more sense.
Publishers that publish articles on a wide variety of topics often have category pages that segment these topics, and in such cases it’s important that the link resides on a page within the right topical category. The rule of thumb here is to make sure the link makes logical sense for your readers.
4. Contextual Relevance
The content surrounding your link is also important. Text before and after a link serves as contextual relevance for the destination page of the link, helping Google determine how the link relates to the content in which it’s placed. This effect is most prominent in the sentence in which the link resides, followed by the paragraph in which it resides, followed by the body of the entire article in which it resides.
5. Anchor Text
The anchor text of your link is taken into consideration as well; this is the clickable text in which your link is “housed.” Several years ago, before the launch of Google’s Penguin algorithm, it was considered best practice to use anchor text reflecting the exact keyword for which you wanted the linked page to rank in search results.
These days, anchor text still plays a role in determining relevance of the linked page, but is also the easiest signal for Google to use to detect manipulation, which puts anyone at risk who is using keyword-rich anchor text excessively.
Nowadays, it’s less important to use keyword-rich anchor text and more important to ensure link anchor text is natural and journalistic. Instead of relying on anchor text to establish relevance of your linked page, rely on contextual and source relevance.
6. Link Destination
When evaluating links, Google will also look at the destination page—the page to which the link points. First and foremost, it should be a strong piece of content that adds value for readers coming from the source article.
Google will examine the title and body of the destination piece, and gauge its usefulness based on its relevance and other quality-indicating factors. Links pass authority to both your overall domain and the individual pages you’re pointing to, so funneling links to one or two core pages can make those pages rank higher than your other content eventually.
Finally, Google will gauge the diversity of your inbound link profile. It’s well-documented that a major factor Google looks for is domain diversity, which is the number of unique domains from which your website has inbound links. For this reason, it’s more valuable, in general, to obtain links from five different publishers than it is to obtain five links from one publisher.
Acquiring multiple links to the same destination page certainly helps to boost its page authority, and is necessary if you’re trying to boost a particular page on your website in the rankings, but doing so too much can make your links seem unnatural and manipulated. This is why, when it comes to link building, diversity of every aspect – anchor text, linking source, destination URL, etc. – is so important.
Think Beyond Google
I also want to mention that while the majority of this article has discussed links in the context of what they can do for your rankings in Google search, that’s only one small part of their overall value. Building links, especially on major publications, also has the potential to send your website referral traffic—in other words, people who encounter your link and click it to read your content.
Your link building strategy should be a balance of looking natural in Google’s eyes, building a network of referral traffic to enjoy, and doing what’s best for your readers and users. It’s a balance you’ll have to strike carefully, but the results are worth it.