Measurement & attribution
Share of search
Share of search is a brand's proportion of category search volume - searches for your brand divided by searches for all brands in the set. It behaves as an accessible, timely proxy for relative demand and often moves ahead of market share.
In practice
Its appeal is practicality: search volume data is available, frequent and comparable, making share of search a useful demand gauge between brand studies.
Movements need interpretation - launches, PR, crises and seasonality all move search - but the trend line is one of the better free demand signals available to planners.