Share of Search
Share of search is your brand's searches divided by the searches for every brand in your category, often taken from free Google Trends data. Les Binet, then head of effectiveness at adam&eveDDB, called it share of search and presented it as a new metric at the IPA's EffWorks Global conference in October 2020. He found it tracked market share.
Source: IPA, Binet presents fast, cheap, predictive Share of Search metric to EffWorks Global 2020 Conference (October 14, 2020), checked October 29, 2026
What Share of Search means for your business
Binet tested it on cars, energy and mobile phones, where the rival brands are easy to list. A local business can borrow the idea on a smaller scale: compare searches for your name with searches for the few names your buyers weigh you against. We'd be careful with small names, where a handful of searches can swing the share a long way.
Binet was plain about its limits. The IPA's write-up of his talk says it isn't a perfect predictor, because price and other things affect whether interest turns into sales, and not every search is good news. In the talk itself, he showed searches for Volkswagen jumping during its emissions scandal while its market share fell.
AI answers add a wrinkle. If they start naming you more often, more people may look you up, and your share can rise with no ad spend behind it. We'd read that as a good sign without crediting any one channel for it.
If you'd like to know whether more people are looking for you by name than last year, the searches we track for that are in each quarterly report.
Last reviewed October 29, 2026. All terms
How AI answers it today
On October 29, 2026, ChatGPT credited the IPA's research and cited its pages, without naming Binet. Google's AI Overview took its definition from a Semrush guide, cited SEO tool vendors and marketing sites, and linked the IPA's talk page for the market share findings.
Our run through ChatGPT and Google's AI Overview, October 29, 2026. A sample, not what every buyer sees.
Related terms in measurement
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