Definition
Share of voice is the share of all visibility in a market that your brand owns. The term comes from advertising — your slice of total media spend in a category — but in search it means your share of rankings and estimated clicks on a fixed set of keywords, and in AI answers how often you are mentioned versus your competitors for the same questions. It is one number that says: of all the times someone searches in this market, how often do they see you?
Share of voice is a better steering metric than average position or the number of top-10 rankings. An average position ignores that position one produces ten times more clicks than position ten, and it counts a niche keyword as heavily as a head term. Share of voice weights each ranking by search volume and expected click-through rate, adds that up for a whole cluster and sets it against the competition. That way you see growth or loss even when your positions look stable.
In classic search you calculate it like this: pick a cluster of keywords, fetch the rankings for you and your competitors, multiply for each keyword the search volume by the click-through rate of that position, add up the results and divide your total by the total of all players combined. A cluster of fifty keywords where you sit at positions three to five for most of them and one competitor sits at position one shows immediately how large that difference in clicks really is.
In AI answers there is no position, so you count mentions. You put a fixed set of questions repeatedly to ChatGPT, Gemini, Perplexity and Google AI Mode (prompt sampling), record per answer which brands are mentioned, recommended or cited, and divide your mentions by all brand mentions combined. Because answers vary from run to run, you need several rounds for a reliable figure, and because engines use different sources, you measure them separately. A mention as 'also an option' weighs less than a recommendation with a link.
The value lies in comparison: per cluster, per engine and over time. A low share of voice in a cluster where a competitor scores high is a concrete gap with a concrete cause — missing pages, a weaker brand description or content that does not answer the question directly. Traze calculates share of voice per cluster and per engine and plans the content that should close the difference.