What Role Does CTR Play in SEO?

Megan Duffy

• SEO

One of the many debates within the SEO space is whether clickthrough rate, or CTR, affects search results. At first glance, the importance of CTR in SEO seems obvious. After all, CTR measures the number of people who click on a search result and search engines want to show people the most relevant results.

Wouldn’t the most relevant search results be the ones people click on the most?

However, the answer is not that simple, hence: the debate on the importance of CTR in SEO.

Search Engine Algorithms

Search engines like Google include hundreds of factors in their search algorithm to measure the relevance of pages on the internet. Google is not always clear on how much each of those factors matters for SEO. The importance of CTR on search engine performance is one of those factors that about which Google has been a bit vague.

But there’s new data (qualitative and quantitative) that strongly suggests that Google does use CTR to determine page rankings.

Paul Haahr, a Google Ranking Engineer said that one of the things Google does to determine the relevance of search results is to “look for changes in click patterns.”

Of course, ‘changes in click patterns’ doesn’t necessarily mean clickthrough rate, so let’s look at some numbers to paint a fuller picture. Larry Kim, the founder of WordStream, conducted the following experiment:

The Hypothesis: CTR in SEO Efforts Affects Search Engine Results

RankBrain—a machine-learning program that Google is rolling out—is used to measure pages with limited data. Presumably, the end goal is for Google to be less reliant on links and more focused on relevance.

CTR is one of the best measures of both engagement and relevance, with some limitations.  As such, many people suspect that RankBrain is using CTR as a critical measure for ranking pages.

The Experiment

Since Google (at the time of the experiment) is only using RankBrain for long-tail keywords, Larry Kim from MobileMonkey measured the effect of CTR on search engine result positions for long-tail keywords and head terms. By separating long-tail keywords and head terms, the experiment would isolate the effect of CTR on search engine results.

The experiment also distinguished between paid and organic search.

The Results

By comparing click-through rates and organic search positions for 1000 keywords, Kim found that long-tail keywords ranked in position one on Google had an average CTR of 33 percent. Alternatively, the head terms he measured that were in the first position on Google had an average CTR of 17.5 percent.

The numbers are similarly spread as you go down the search results. Long-tail keywords in position two had a clickthrough rate of about 22 percent, whereas head terms in position two had a CTR of 13 percent. The spread between clickthrough rates appears to tighten, though, as you go further down the page from position six to ten.

For paid searches, the results were similar, but the differences were a bit less pronounced. Interestingly, the spread in clickthrough rate was most pronounced on lower search positions.

What does it mean for CTR in SEO?

It seems highly likely that clickthrough rate is a key measure in Google’s ranking algorithm. Even if CTR is not directly responsible for higher search rankings, it’s indirectly responsible, because you’ll always rely on people clicking on your content to drive engagement, social shares, and brand awareness.

Want to learn more about how CTR optimization will help your business’ SEO efforts? Reach out to the SEO team at Volume Nine – we’re here to help!