Keyword search volume is the number of searches a keyword receives during a given period (usually per month). It is a commonly-used, descriptive statistic in SEO and content marketing that helps compare and value a group of keywords.
For example, let's say we are building an SEO-driven editorial calendar and have a spreadsheet containing 100 keywords with their respective search volumes. Assume the difficulty to rank for each keyword and the value from a business perspective are equal. A common approach to prioritizing content creation is to create content for the highest search volume terms first.
Using keyword search volume in this way can be misleading.
In this article, you're going to learn why that's the case and then what you should use in place of keyword search volume.
The Problem With Keyword Search Volume
There is a fundamental issue with search volume:
It doesn't account for the click-through rate (CTR) on the Google search engine results page (SERP) for that unique keyword.
Multiple factors contribute to the CTR for a given SERP:
- SERP features
- The intent of the search
- And the quality of the results.
To see an extreme example of this, Google "pounds to kilograms converter."
You'll notice Google has built in a pounds to kilograms converter directly into the SERP!
There's no reason to click through to any of the results because Google is answering the query directly in the SERP.
Even if this particular keyword gets thousands of searches per month, it'd be a massive waste of resources to try to create a pounds to kilograms converter on your site.
The only site seeing any of this traffic is google.com.
Rand Fishkin conducted a study showing that in June of 2019 (for the first time ever), the majority of browser-based searches in Google resulted in zero clicks.
So how do you account for varying click-through rates by keyword?
The answer: start using clicks per search.
What Is Clicks Per Search?
Clicks per search (CPS) is a ratio of the number of clicks for each search.
If the ratio is 2, that means there are two clicks for each search. If the ratio is .5, that means there is one click for every two searches.
For our pounds to kilograms converter example above, the CPS is going to be very low because there will be more searches than clicks.
You can probably guess that the lower the CPS, the higher the probability that there are SERP features present in the SERP for that keyword.
A higher CPS means that searchers are, on average, clicking through to more than one result.
Here are a few examples that could cause this to happen:
- The results for a given query are poor. Searchers are reading through many results to get a sufficient answer.
- The query is a "your money or your life" (YMYL) query. Searchers are more engaged with the results and spend more time researching because the topics are impactful on their life/money.
What To Use Instead of Keyword Search Volume
The main reason we use keyword search volume is that we want a value that describes how much traffic we can drive to our website by creating a new page.
So is there a better value we can use? Yes, traffic potential.
Conceptually Understanding Traffic Potential
Here's a basic traffic potential calculation you'll often see:
Search Volume * Generic Positional CTR = Keyword Traffic Potential
Generic positional CTR is the generic click-through rate percentage for the position in the SERP a URL ranks at. "Generic" means that the CTR does not adjust for each keyword.
When we look at rankability at my agency, we usually think about the following factors:
- Authority/Strength of the domain (metrics like Domain Rating and Domain Authority)
- Keyword difficulty from a backlink perspective
- Content quality (including on-page optimization and UX)
Using these three factors, you can determine a "rankable position." Next, you apply a generic CTR curve (like the one at Advanced Web Rankings) to determine the generic positional CTR.
There are a few significant issues here:
- The formula uses a generic CTR curve, not one specific to the SERP
- The formula doesn't account for CPS
Let's fix it and add CPS and Keyword Specific Positional CTR to the formula:
CPS * Search Volume * Keyword Specific Positional CTR = Keyword Traffic Potential
The above formula accounts for the number of clicks per search for a given keyword, giving you a much clearer picture of the actual traffic potential.
Even though we calculated the traffic potential for a given keyword, this isn't necessarily useful in practice.
We're only calculating this for an individual keyword. When you create a page around a topic, that page will typically rank for a lot more than just a single keyword.
To get an accurate idea of what the actual traffic potential for that page is, you need to SUM the traffic potential for each keyword the page ranks for:
SUM ( CPS * Search Volume * SERP Specific Positional CTR ) = Total Traffic Potential
How To Find Traffic Potential
Here's an easy way to get traffic potential so you can use it in your analysis.
At my agency, we use Ahrefs to do this because we've verified that they use CPS and SERP specific CTR curves in their organic traffic calculation. If you use a different tool, check to see how they are calculating organic traffic.
First, determine what the main keyword is for the page you want to create.
Second, determine what position is "rankable."
Next, Google the main keyword and copy the URL that currently ranks in the position you deemed as "rankable."
Finally, paste the URL into Ahrefs Site Explorer to get the organic traffic estimation. Use this as your traffic potential value.
Using This In Practice
At our agency, we build an SEO driven editorial calendar and opportunity model. We add all the topics to the editorial calendar and then calculate a priority score for each topic so we can prioritize the topics with the highest potential value first.
We build priority scores based off:
- Traffic potential
- Keyword difficulty based on links
- The business value of the keyword
- Authority/strength of the domain versus the competitors
Traffic potential instead of search volume is integral to this priority calculation. If we used search volume, but the keyword has a very low CPS, we would be severely overestimating the traffic from the keyword, and the priority score would be unreliable.