What is share of search?

Share of search is your brand’s slice of total branded search volume in a category: searches for your name divided by searches for yours and your competitors’ combined. Les Binet’s research popularized it as a cheap, forward-looking proxy for market share — people search for brands before they buy them, so shifts in search share tend to precede shifts in revenue share by months.

It is one of the few competitive metrics available from entirely public data, and its movement is the headline: a competitor’s search volume accelerating past yours is early warning that their marketing is compounding. It differs from share of voice, which measures visibility you project; share of search measures demand buyers volunteer.