What is Share of Voice in AI?
Share of voice in AI is the percentage of AI-generated answers, across a fixed set of tracked prompts, in which your brand is mentioned or recommended — the core visibility metric for GEO, tracked engine by engine and against named competitors.
Classic SEO has rank position: are you #1, #3, #11 for a keyword. AI answers don't have a stable position to measure, because the response is generated fresh each time and can vary by engine, phrasing, and even between two runs of the same prompt on the same day. Share of voice is the metric GEO uses instead: run a representative set of real buyer questions against each answer engine on a schedule, and measure what fraction of the responses mention your brand at all, and how you rank against the specific competitors named alongside you.
A useful share-of-voice number is always relative, never absolute. "We're mentioned in 40% of tracked answers" only means something next to "our closest competitor is mentioned in 75%." It's also engine-specific — a brand can have strong share of voice in Perplexity (which favors well-sourced, citation-dense content) while being nearly invisible in consumer ChatGPT answers that don't use search grounding at all.
Because the underlying answers are non-deterministic, share of voice is measured as a rate over repeated runs and time, not a one-off snapshot — the same discipline prompt tracking exists to support.