Share of search compares how often people search for your brand with how often they search for competing brands in the same category. It is calculated as your branded search volume divided by the total branded volume for the category. The metric was popularized by marketing effectiveness researcher Les Binet, who presented it as a possible leading indicator of market share. It measures brand demand, not SEO performance, and it complements share of voice, which measures visibility in results.
How to calculate it
Choose a fixed set of competing brands and pull branded search volume for each over the same period. Google Trends works for relative comparisons; keyword tools provide estimated absolute volumes. Exclude brand terms that are also common words, or filter them carefully, because they inflate volume with unrelated searches.
share of search = your branded searches / total branded searches for all brands in the set
Illustrative example:
Brand A: 4,000 Brand B: 10,000 Brand C: 6,000
Brand A share of search = 4,000 / 20,000 = 20%What it tells you
Rising share of search suggests growing awareness and interest relative to competitors, often after brand campaigns, launches or press coverage. It is most useful as a trend over months. The link to market share has been discussed for consumer categories; evidence for niche B2B software is thinner, and small search volumes make the metric noisy.
Example
Tracking the effect of a conference push
Imagine Pinemarket, a fictional sales enablement tool, tracks share of search monthly against four competitors using Google Trends. After a quarter of conference sponsorships and podcast appearances, its line rises relative to the others.
The team reports it alongside pipeline data, noting that the volumes are small and the trend should be confirmed over several more months.
Common mistakes
Including ambiguous brand names
A brand named after a common word picks up unrelated searches, distorting the share.
Changing the competitor set
Adding or dropping brands changes the denominator. Keep the set stable for trend comparisons.
Questions
It uses search data, but it measures brand demand rather than SEO results. SEO teams often report it because they already work with search data.
