Prompt Coverage

Also called: Coverage Rate

Common prompts: "what is prompt coverage," "AI prompt coverage measurement," "how to measure prompt coverage"

Definition

Prompt Coverage is the percentage of category-defining buyer-intent prompts that surface a brand in an AI engine's answer at all — independent of citation share or recommendation. It is the diagnostic of structural absence: if a brand misses the prompt entirely, every downstream metric is moot.

Why it matters

A brand with strong sentiment on the 12 prompts where it surfaces and zero presence on the other 48 has a Prompt Coverage problem, not a sentiment problem. Coverage is the precondition for everything else. Communications strategy that targets quality of mention without measuring coverage first invests against the wrong constraint. Coverage is structural — built through retrieval anchors and earned media — and changes the floor of every other metric.

Example

A skincare brand tests 60 buyer-intent prompts. It appears in answers for 18 of them. Within those 18, sentiment is positive and Citation Share is 22%. But the other 42 prompts produce answers where the brand is never mentioned — full coverage failures. The brief shifts: build retrieval anchors on the missing 42, not refine the messaging on the existing 18.