Share of Search: What It Measures, and What It Can’t Tell You

Share of search is touted as a fast, cheap read on brand health. But conflicting definitions and explanations make it difficult to understand the metric’s value. These explanations tend to describe share of search as a measure of how well a brand performs in search, but that’s not the full picture. 

In this article, you’ll learn what share of search actually measures, what the research behind it does and doesn’t prove, how to build the competitor set the whole calculation rests on and how to read a change once you see one. 

Key Takeaways: Share of Search 

• Share of search measures how much of the category’s branded search demand goes to your brand name — not how well your pages rank. 

• The Institute of Practitioners in Advertising (IPA) found it corresponds to about 83% of market share, on average, and said that the relationship is a correlation rather than a cause. 

• The competitor set is the denominator, so whoever decides who belongs in the category decides the number. 

• A single figure can move because your brand grew, a competitor shrank, the category shifted or the measurement changed. 

• Understanding what the metric means and how to activate it properly is challenging, and having a measurement and insights partner is valuable to contextualize and synthesize share of search data. 

What Is Share of Search? 

Share of search is the proportion of category search demand that goes to a specific brand name. 

To calculate share of search, divide your brand’s search volume by the combined volume for every brand in the competitor set, then multiply by 100. 

The metric emerged out of advertising effectiveness research rather than search software. The data is available to anyone, it updates continuously and it costs nothing to calculate. That’s why adoption of the share of search metric is so high. 

Share of Search vs. Share of Voice vs. Market Share 

Share of search, share of voice and market share measure three different things and constantly get blurred together. It’s important to distinguish between them and understand how they complement one another to build a more accurate and robust picture of your brand’s performance. 

The following table outlines the differences between the three metrics. 

The three metrics sit in sequence: spend influences demand, and demand precedes sales. That’s why share of search reads as an early indicator rather than a lagging one. 

Share of Search Measures Demand, Not Visibility 

Share of search counts how many people search for a brand by name. It doesn’t reveal anything about how well the brand’s pages rank. 

A brand can hold the top organic position for every keyword term it targets and still lose ground in search share, because ranking well serves demand that already exists rather than creating more. Ranking is a measure of your pages; share of search is a measure of your brand.  

And while brand monitoring tracks what people say, search share tracks what they look for. A team that reads it as a ranking score will spend against it in the wrong place and wonder why the metric doesn’t improve.  

What the Research Actually Found 

The headline finding is that share of search corresponds to roughly 83% of a brand’s market share, on average.  

Les Binet and James Hankins introduced the metric at the IPA’s EffWorks Global Conference in 2020, and Hankins returned in 2021 with the findings of the IPA think tank formed to test it — 30 case studies across 12 categories and seven countries. Binet’s own analysis found the metric leads market share, with the lead time varying by category, up to about a year in automotive and shorter in mobile handsets, for example. 

At the same time, the metric isn’t without some shortcomings that are important to understand. The IPA states plainly that these relationships are correlative, not causal, and Hankins stressed correlation over causation when he presented the findings. Binet’s characterization is that the metric isn’t a silver bullet and the data needs to be interpreted with care.  

How to Run a Share of Search Analysis 

This section will walk you through everything you need to know to perform your own share of search analysis. The arithmetic behind share of search is straightforward, and every decision that determines the answer happens in the equation before you divide.

Decide Who Is in the Competitor Set 

The competitor set is the denominator of the calculation.  

• Why it decides the answer: Every brand added to the set raises the denominator and lowers your share. This makes the number a judgment call before it’s a measurement. 

• How to choose: Build the set from the brands a buyer actually weighs against yours, not from the full list of companies in the category. A definition that’s too broad flatters everyone; too narrow, and the number flatters you. 

• Keep it fixed: Changing the set between calculations makes the trend meaningless. If it has to change, restate the earlier periods on the new set so the comparison still holds. 

Capture How People Actually Type Your Brand 

Not every consumer uses the full, official name when referring to (or searching for) a brand, so include all possible names that consumers may use. 

• Variants and misspellings: Shortened names, common misspellings and nicknames all carry real volume, and counting only the official spelling understates you. 

• Generic or ambiguous names: A brand name that’s also an ordinary word collects unrelated searches. More than creating noise in the data, it can also make the metric unusable. 

• Multi-category brands: A parent brand selling across several categories can’t be compared cleanly against a single-category competitor

Smooth the Data Before You Read It 

The rolling average is part of the IPA method, not an optional extra.  

The IPA method uses a six-to-twelve-month rolling average, and, without it, a single campaign burst or seasonal peak would read as a change in overall brand health. The smoothing from the rolling average is what makes this a brand measure rather than a campaign measure. It’s the step that gets skipped most often, and skipping it produces most of the bad readings. 

Which Share of Search Tool Should You Use? 

The share of search tool you choose is less important than the method outlined in the previous section, but the tool is still an important factor for analyzing and streamlining your share of search analysis.  

• Free trend tools: Google Trends is the source that the original IPA method used. It returns relative interest indexed from 0 to 100 rather than absolute volumes, so it shows direction well and exact share poorly. It returns nothing at all for brands below its volume floor. 

• Keyword volume tools: The SEO platforms report estimated monthly volumes, which lets you calculate a real percentage. These estimates are modeled and differ between platforms, so the figure depends partly on which one you opened. 

• Dedicated and research platforms: Several products calculate the metric directly, and brand measurement programs increasingly carry it as one input alongside survey data. 

Whichever source you choose, the comparison only holds if every brand in the competitor set is measured the same way, in the same tool, over the same period of time. 

How to Increase Share of Search 

Share of search rises when more people look for the brand by name, so broader brand initiatives to build recall directly impact share of search. 

• Brand advertising that reaches past the in-market audience: This is a measure of mental availability, and mental availability is built among people who aren’t buying yet. This is the lever the original consumer insights research was designed to measure. 

• Distinctive assets people can actually recall: A name, a look or a line someone can retrieve unprompted is what turns exposure into a search. Advertising nobody remembers moves awareness scores and very little else. 

• Earned coverage and third-party presence: Showing up where the category gets discussed puts the brand in front of people while they’re forming a shortlist, which is upstream of the search. 

• Search and content work, in its real role: SEO captures existing demand and can indirectly grow branded search over time. However, treating it as the primary lever is a mistake. 

Increase share of search can come from your own growth or from a competitor’s decline, and the two call for completely different responses, even though the number would look identical.

What Share of Search Can’t Tell You 

Share of search is a ratio, so it registers that something moved — but it doesn’t tell you what moved or why.  

• Your brand grew: More people searched for your brand by name.  

• A competitor shrank: Your share rose because the denominator fell. Nothing about your brand changed. 

• The category moved: Total demand rose or fell for reasons outside any brand in the set: seasonality, a news cycle, a regulatory change, etc. 

• The measurement changed: A brand entered or left the set, a tool revised its volume model or a name became ambiguous partway through the measurement period. 

Share of search is a prompt to investigate, not a finding on its own. Figuring out which of these four scenarios drove the shift takes data not included in the ratio — what people think of the brand, why they went looking and whether they bought. The difference between knowing something moved and knowing why makes a great case for pairing share of search with attitudinal measurement in your brand health tracking program.  

Brand Measurement with Material 

Share of search is a real signal, and it’s most valuable to a team that already knows what else is true about their brand. It is also an unusually cheap one to capture and integrate into your brand measurement infrastructure. 

Having a measurement and insights partner is valuable to contextualize and synthesize share of search data. Material builds brand measurement programs that put signals like this one alongside the attitudinal data explaining them, so a movement in the metric arrives with a reason attached, rather than as a number somebody has to account for in a meeting.  programs that put signals like this one alongside the attitudinal data explaining them, so a movement in the metric arrives with a reason attached, rather than as a number somebody has to account for in a meeting.  

Want to learn how Material can help your brand accurately measure search share, activate it into a clear, data-driven picture of how your brand is performing and help you choose the next best step to increase market share? Start the conversation.