Keyword search volume is one of the most frequently used metrics for keyword research, yet it is highly misunderstood.
This guide will clear up some of the misconceptions about search volume, provide ways to use it correctly, and detail several use cases for SEO.
What is Keyword Search Volume?
Keyword search volume is the number of searches for a given keyword on a certain search engine over a specified period of time.
How is Keyword Search Volume Used?
In organic search optimization, the primary use of keyword search volume is in keyword research for discovering the following useful SEO information (which is expanded upon in the final section of this guide):
- The traffic-driving potential of a keyword.
- The competitive difficulty level of a keyword.
- Creating traffic estimates.
- Determining seasonality.
How is Keyword Search Volume Determined?
There are two commonly used ways you can determine search volume for keywords.
Google Ads Keyword Planner
The first and most common is from what search engines such as Google report themselves. Google reports this in its Keyword Planner.
A few things to note about this resource:
- It is intended for researching Google Ads-related keywords, so not all keywords are reported.
- You must have a Google Ads account to access Keyword Planner.
- Volume numbers in Keyword Planner are broad estimates and are often aggregated, combining numbers for similar keywords. They are also rounded off.
- Volume reports in Keyword Planner have a time lag, so it is not useful for newer or up-and-coming keywords.
By default, Keyword Planner reports average search volume, the average of the last 12 months of search volume. So the reported figure is not for the most recent month but instead is the total volume for the past year divided by 12.
Also, keep in mind that Keyword Planner does not distinguish things like device types or mobile vs. desktop. The reported numbers are estimates based on an aggregation of various devices and search mediums.
Google is hiding search volume for a growing number of keywords that might be in socially or legally sensitive areas, too, even if those keywords can still generate Google ads.
And Google often reports zero search volume for keywords where clickstream data-based tools show volume exists.
This example from Google Keyword Planner shows how its keyword aggregation can cause false assumptions:
Screenshot from Google Keyword Planner, October 2021It’s very likely that far more people search for [HDMI] than for its spelled-out equivalent, [High-Definition Multimedia Interface]. Yet Keyword Planner shows them as having the same search volume.
Clickstream Data
The other source for search volume numbers is clickstream data. This is data collected from a sampling of actual users, often by means of a browser extension that users install voluntarily.
It’s important to note that clickstream data is still an estimate. Its accuracy will depend on the number and kind of users polled, the polling methodology, and the mathematics used to extrapolate the estimate.
The advantages of clickstream-based search volume data over Keyword Planner include:
- It is not limited to keywords that show ads in Google, or keywords that are not “censored” by Google.
- It can distinguish between subtle variants of a keyword.
- It can be more real-time, providing more timely data and including newer and trending keywords.
However, as noted above, you should keep in mind that any volume estimates based on clickstream data are only as good as the data sources and their methodologies.
How Reliable is Search Volume Data?
As described in the previous section, all available search volume data is based on estimates and extrapolations.
There is no actual search volume data available, nor is there likely to ever be.
With that said, even estimated search volume can be useful. It is not necessary to have exact search volume numbers to do valid comparisons between keywords.
If the volume estimates are drawn from the same source and using the same methodology, then the relative distance between any two keywords and their overall trend comparison over time should be accurate enough to make sound judgments.
Also, keep in mind that search volume is often seasonal; it does not necessarily remain constant.
Should I Ignore Low-Volume Keywords for SEO?
Short answer: No!
Longer answer: As in all things SEO, it depends.
While it might seem to make sense to ignore low-volume searches based on an assumption that they will be low traffic generators, that supposition doesn’t bear out in real-world experience.
First of all, remember that it is a myth that search volume and traffic are necessarily correlated.
Second, lower-volume keywords can be valuable “team players” in content strategies.
Low-Volume Keywords and Topic Clustering
Topic clusters (sometimes called “content hubs” or other names) consist of a “pillar” or “hub” page usually targeted at the main, higher volume “head term” for a topic important to a site.
There are then many other “spoke” or “satellite” content pages linking to it that are about more finely targeted subtopics of the main topic.
When strategically executed, the topic cluster approach can bring significant results because it signals to search engines that your site is an authority on the main topic and that you have covered it comprehensively.
It is likely that engines like Google prefer to send users to sites that are able to satisfy more of the user’s related needs, the things they might also want to know about the given topic.
Lower-volume keywords if relevant to the pillar topic can be good sources of content ideas for spoke content to build around your main topics.
Low volume keywords are often also longer-tail keywords, meaning they relate to a much more specific intent of the searcher than head terms.
That means that while pages optimized for any one long-tail keyword may not be huge traffic drivers in and of themselves, they can:
- When viewed in aggregate, together bring in significant traffic the site might not have drawn otherwise.
- Drive more conversions since they are targeted at a particular user intent, rather than just general information.
Low-Volume Keywords and Niche Industries
The other application where lower-volume keywords become important players is for industries where there simply isn’t a lot of search volume to be had, so-called “niche” industries or topics.
While in SEO we tend to focus on and celebrate the big wins, the optimizations that result in huge traffic numbers, in reality, there are a great many businesses that depend on and even thrive on winning with lower, but very targeted, traffic.
However, since Google’s Keyword Planner tends to underreport or even exclude or “zero” many lower-volume keywords, it may be necessary for SEO pros in niche industries to turn to more sophisticated keyword tools that use their own sources and calculations for search volume.
Particularly useful for this application are tools that enable you to do keyword research based on very granular industry categories.
Of course, good competitive research using established sites in your niche can also help uncover the valuable but harder-to-find keywords you may want to target.
Is Google Trends a Search Volume Tool?
Google Trends is a useful free tool that displays the relative popularity of a search term over time.
That may sound like the same thing as “search volume,” but there are subtle yet significant differences.
The primary metric in Google Trends is not the actual volume of searches for a topic. It is a normalized “score” on a 0-100 scale representing the relative search frequency of a topic compared to the proportion of all searches for the topic over time.
Even so, Trends can still be a valuable addition to your keyword research as it helps you understand how popular your topics are and whether you can expect to be riding a rising wave for a given topic.
How to Use Search Volume for SEO
Now that you have a better understanding of what search volume is, how it’s determined, and the various restrictions and limitations involved, let’s move on to its practical applications.
Here are the main uses of search volume data for SEO.
1. Determining the Potential Value of a Keyword
While it seems intuitive that the more search volume a keyword gets the more traffic it can drive, in reality, there are many other factors that affect traffic-driving potential including:
- The relevance of the keyword to your site and audience.
- The actual click-through rate on searches.
The latter can be greatly affected by features on the search page which may satisfy a user’s query without them clicking through to a site.
So the amount of search volume shown for a keyword should be only one factor to be considered when assessing priorities for keyword targeting.
2. Assessing the Relative Difficulty Level of a Keyword
Generally, the higher the volume of a keyword the more competition for it in the SERPs.
That means (again, in general) that it will take much more effort to high-rank a higher volume keyword.
Many keyword research tools express this in terms of a keyword difficulty score, with search volume as one of several factors in determining that score.
Actually, a well-constructed keyword difficulty score may be more valuable than search volume alone, simply because it does account for those other factors.
It can be the case that a high-volume keyword has relatively low difficulty, but when that occurs you need to dig deeper to find out why.
It could be you’ve stumbled upon an opportunity your competition hasn’t discovered yet, but it could also mean that this keyword simply won’t create useful traffic for you.
3. Creating Traffic Potential Estimates (Maybe)
I deliberately used the word “creating” above because it is a myth that higher search volume correlates to higher traffic potential.
It can mean that since of course (all other conditions being favorable) more people in the search pipeline means more people who could potentially click on your result.
But that “all other conditions” caveat in the previous sentence is not insignificant.
For example, it may be the case that the top few results for a high-volume keyword are so good and so relevant that they swallow up most of the clicks. Even if you got into the top ten results, you might not get a lot from it.
Another possibility that undermines the traffic potential of a popular search are features such as Featured Snippets. These might satisfy the need of many searchers, resulting in a so-called zero-click situation for the organic web results on the page.
For those reasons, keyword research tools often use formulas that combine search volume with estimated click-through rate, and sometimes other factors, to determine potential traffic from a keyword.
4. Determining Seasonality
A tool that shows the month-by-month trend of keyword search volume can be your best guide to how much the time of year affects interest in your keyword.
Remember that the number reported by the Google Ads Keyword Planner is a 12-month average, so it gives no indication of seasonal variations.
In the case of an ecommerce site, that knowledge can be particularly invaluable in knowing when to step up efforts for a particular product or category.
For example, here’s a 24-month search volume trend for “heavy coats.”
Screenshot from seoClarity, October 2021Not surprisingly, searches for heavy coats start to climb in the fall and peak in November.
However, not all seasonality is that intuitive, so a tool that shows it can uncover hidden insights that may be of value beyond SEO.
Conclusion: The Value of Search Volume in SEO
Search volume is without a doubt a key metric for effective keyword research.
However, the researcher should be aware of the limitations of search volume metrics as well as ways to enhance the information that search volume data provides to enable more accurate assessments.
If you understand all these nuances about search volume, it will become a more valuable part of your own research and keyword assessment process.
More Resources:
- SEO Keyword Research: 15 of the Biggest Mistakes You MUST Avoid
- 44 Free Tools to Help You Find What People Search For
- How to Do Keyword Research for SEO: The Ultimate Guide
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