AI SEO Glossary

Prompt Share is the percentage of a defined set of relevant prompts for which your brand appears in the AI-generated response, expressed as a proportion of the total prompts tested. If you test 200 prompts relevant to your product category and your brand appears in 60 of the generated responses, your Prompt Share is 30 percent. It is closely related to Share of Voice but focuses specifically on the breadth of query coverage rather than the depth of mentions within each response. High Prompt Share means your brand is appearing across a wide range of relevant queries, not just the ones you explicitly optimize for.

Measuring Prompt Share requires building a representative library of prompts that reflects the full range of queries your target audience uses when researching your category, running those prompts systematically through the AI platforms you are monitoring, and recording which prompts trigger a brand mention versus which do not. The metric is then calculated as mentions divided by total prompts tested. Over successive testing periods, trends in Prompt Share reveal whether your AI visibility is expanding, holding steady, or declining, which serves as an early indicator of whether your GEO and content efforts are working.

Why it matters: Prompt Share gives you a breadth metric for AI visibility. A brand with narrow Prompt Share is heavily dependent on a small set of queries, which is a fragile position.