Prompt coverage measures how many of the questions buyers ask about your category your content actually answers.
Nobody researches a purchase with a single question. Over a few weeks, a buyer might ask an AI engine what a category even is, what it costs, how two vendors stack up, whether it's overkill for a five-person team. Prompt coverage is the fraction of that real question set you have a citable answer for.
Breadth is what separates it from citation share. Citation share asks how often you win the questions you already compete on. Prompt coverage asks how many you're in the running for at all. The two move independently: six sharp pages can earn strong citation share while leaving you invisible on the thirty other questions buyers bring to an engine.
Why it matters
You can't be cited for a question none of your pages answer. That's what makes a coverage gap different from a quality problem. No amount of polishing an existing page closes it, because the fix is a page that doesn't exist yet. Writing those missing pages usually lifts overall visibility faster than reworking the ones you have, which is why coverage is often the cheapest lever a team has.
Closing the gap
Start by writing down the questions buyers actually put to an AI engine, then hold each one against your site. Some already answer cleanly. Plenty circle the answer without ever stating it, and a good number aren't there at all. Work the list from the bottom of the funnel up, since the questions nearest a purchase are the ones worth capturing first.
If buyers ask forty distinct questions and your content answers fifteen, that's 37.5% coverage. The other twenty-five are answers a competitor wins by default, not on the merits but because you never showed up for them.
Related terms
- Citation Share: how often you win the questions you do cover
- Demand Capture: converting the intent behind high-value prompts
- Answer Engine Optimization (AEO): how each covered page earns its citation