Study: Which Link Metric Correlates Closest to Organic Visibility?

Throughout my career, most of my teams’ digital PR strategies for clients have consisted of closing link gaps, creating new ones, and earning as many high-tier links as possible. The goal was always the same: get our clients' websites to the top of the search engine result pages (SERPs) and outranking their competitors.

To that end, we’ve earned press coverage for clients on every top-tier publisher you can think of, including "dream publishers'' like CNN, the New York Times, Washington Post, and Business Insider. We’ve even had dozens of campaigns go viral, earning thousands of links and hundreds of thousands of social shares, all resulting from sending a single outreach email to a journalist.

"What's wrong with that?" you might be asking. "It sounds like a successful strategy."

While "going viral" might not carry the same weight it once did, I'll be the first to admit it – there is hardly a more exciting feeling when working in digital PR. And we all know that link volume combined with high authority links will help you rise in the ranks of the SERPs. So, actually, there’s nothing intrinsically wrong with that strategy.

But when all you care about is lots of links and going viral, sometimes you miss the mark on something that matters just as much, if not more: relevance.

Since 2019, Google has acknowledged that it uses Natural Language Understanding (NLU) when assessing the relevancy and intent of users' search queries. So why is no one measuring relevance when it comes to link profiles?

The team at Journey Further sought to do just that — and in our latest study, we demonstrate why link relevance is more important than ever, and how a relevance-led approach can outperform larger and more authoritative websites time and time again.

What does it mean to be relevant in digital PR?

Like most things that catch fire in our industry, "relevance" has become a bit of a buzzword in digital PR. But what does it mean, really?

When you think about relevance, it's simple. Ask yourself:

• Does this campaign relate to the client's product or service?

• Does it have target keywords in it?

• Does it talk about the main topics we want to target?

• Does it answer the search intent?

• Does it make sense for the client to be considered an authority and/or a trusted source on this topic?

If you answered no to most of these, you might want to go back to the drawing board.

For some clients, it can be difficult to come up with an idea that's both relevant and newsworthy. The most relevant idea in the world will not earn links if it's boring, and that's the challenge we all face every day when creating digital PR campaigns for our clients.

Though it's difficult, it's in your clients' best interest for you to think outside the box in ideation and come up with both relevant and link-worthy digital PR ideas — you'll understand why after seeing the data from our latest study.

How do you measure content relevance?

Beyond manually determining relevance with those questions above, what if there was a data-driven way?

Steve Walker, the technology director at Journey Further, found this kind of analysis to be resource-intensive and prone to error. Humans aren't as good at these tasks as machines are, so he created Salient, a free-to-use tool that measures the relevance of your content.

Steve thought, "If Google uses machine learning to measure the relevance of content, why aren't we?"

Using this proprietary technology powered by Natural Language Understanding (NLU) technology is how we can measure the relevance of content, analyzing an entire website's link profile rather than individual articles. Incorporating the IBM Watson Machine Learning API allows us to extract sentiment, recurring keywords and entities, and a relevancy and frequency score for each topic.

Off the back of this insight, we can understand what gaps exist in the relevancy of the link profile. This information then guides our PR and content strategies to drive organic visibility.

Study: Which link metric correlates closest to organic visibility?

So, how important is relevance compared with much-heralded metrics like Domain Authority (DA) and link volume?

In a data-driven attempt to learn which metric is statistically the best driver of organic visibility, our team at Journey Further analyzed the organic rankings of 6,000 commercially valuable keywords, calculating share of voice for a range of competing websites. From there, we measured the correlation of these scores against three link metrics:

1. Number of unique linking domains

2. Domain Authority

3. Topical link profile relevance

In this study, we focused on the home retail sector, with the following focus areas:

Across all 15 sectors, topical link relevance was the only metric that had a positive correlation to organic visibility

The findings of our study show that topical link relevance has the strongest correlation in 10 out of 15 sectors.

Domain Authority had a stronger correlation in five sectors: outdoor/patio, office furniture, bedding, desks, and pillows.

Unique linking domains never had the strongest correlation to organic visibility and, in fact, showed a negative correlation in 6 out of 15 sectors.

However, across all 15 sectors, topical link relevance was the only metric that positively correlated to organic visibility every time.

That's the TL;DR of it, but read on for a deeper look at some individual topic areas and how we came to these figures. View the full study here.

Definitions and Limitations

To better understand the data, let's detail some definitions first:

Correlation coefficient: A linear measure of the correlation between two variables. A value of 0 indicates no association between the two variables. A value greater than 0 indicates a positive association, and a value less than 0 indicates a negative association.

Organic share of voice (SOV): Organic SOV is a metric that represents how much organic traffic a site receives vs. the other sites in that sector for a set of high-traffic keywords. It considers keyword volumes, click-through rates, ranking position, and SERP features. The final SOV is expressed as a percentage of that keyword set's total available search volume. So if your SOV is 25%, you're winning 25% of the clicks for that set.

Topical link relevance: A score that shows the relevance of a keyword or topic to the entire document text or range of pages analyzed - in this case, the text on each page that links back to the sites we analyzed. The higher the number, the more relevant a topic. A score of 0 means that the topic was not relevant at all.

Unique linking domains: The total number of unique domains that link back to each site.

Domain Authority (DA): A ranking score developed by Moz that predicts how likely a website will rank on SERPs. A DA score ranges from 1 to 100, with higher scores corresponding to greater visibility.

Limitations

This study relies on correlation and thus has limitations. Please note that correlation ≠ causation, and because Google historically does not comment on studies, or reveal precisely how the ranking algorithm works, we’ll likely never find causation. However, based on patents mentioning the use of topical relevance in combination with the findings of the correlation studies, we can be confident in the validity of the data.

Relevance vs. Link Volume

As an example, let's look at the bathroom sector. When looking at hundreds of keywords related to bathrooms like bathroom mirrors and bathroom ideas, we found that this sector has over 1.8 million searches per month, with leading home brands competing for share of voice.

After analyzing the backlink profile and relevance score, we then calculate a correlation with that brand's share of voice to determine if there is any connection between this metric and organic visibility.

• Anything below zero has a negative correlation, so there is no connection.

• Anything over zero has a positive correlation.

• The higher the correlation, the stronger the relationship between the metrics and organic visibility.

With a correlation coefficient of .74, it's clear that the metric that is most closely related to organic visibility for the bathroom sector is topical link relevance.

Unique linking domains, in this case, has a negative correlation. For example, IKEA has a backlink profile of more than 406K ULDs, but doesn’t have the biggest market share, which shows that there is no correlation to the link volume and market share.

Relevance vs. Domain Authority

When looking at hundreds of keywords related to dressers, we found that this sector has over 1.6 million searches per month.

Again, we did the same thing here and compared each brand's backlink profile and relevance score to that brand's share of voice.

With a correlation coefficient of .61, we see that topical link relevance is the metric most closely related to organic visibility for the dressers sector.

However, this example demonstrates that all three metrics (relevance, Domain Authority, and link volume) are critical to organic visibility. All three have a very high correlation, which suggests that not only are these metrics correlated, but perhaps they are integral for boosting organic visibility in this sector.

View the full study here. (And feel free to reach out to me directly if you want us to run a free relevance report for you).

In SEO, it's not enough to be popular, you also need to be relevant

Historically, the SEO industry has relied on metrics like Domain Authority and link volume. These two metrics are important, but only provide a portion of the puzzle. Alone, they don't answer Google's primary question: which website is the most relevant for a query?

We've all seen campaigns out in the wild that make us scratch our heads, thinking, "what does this topic have to do with that client?" Think: why is a CBD company pushing out a study on anything but CBD? Why is a company that sells bathroom fixtures creating content about dogs?

When you fail to see the connection between the story and the client, you know they're only thinking of one thing: links.

But, as my colleague Beth Nunnington likes to say, "in SEO, it's not enough to be popular, you also need to be relevant."

Don’t forget, most clients don't want links for links' sake. They want what links bring: increased traffic, better rankings for priority keywords, increased revenue, brand awareness, etc.

And links will only serve those goals when they're relevant.

Don't get me wrong – I still LOVE a CNN placement (and so do clients), but now, I'd also like it to be relevant.