What is query fan-out?
Query fan-out is an answer engine turning one question into several related searches, then retrieving pages for those searches. The extra searches can cover comparisons, constraints, and follow-ups the person did not type. You usually see the effect in the sources and the answer, not a public list of every internal query.
Why it matters for AI visibility
Fan-out matters because the page that wins the exact keyword may not be the page that answers the sub-question the engine actually retrieved. A prompt like “best CRM for agencies” can fan out into pricing, integrations, migration effort, and complaints. If you only publish a single glossy category page, the cited sources may be reviews and docs that answer those parts. Covering fan-out means mapping the follow-ups a buyer needs and answering them in sections or in dedicated pages, with internal links between them. A fan-out tool can suggest likely sub-questions from a seed prompt. It does not reveal the hidden queries an engine ran on a given day. Use suggestions as a checklist against real sales calls, then confirm citations by reading live answers.
Example
The seed question is “accounting software for freelancers.” Related questions a buyer still needs answered include invoicing, tax export, and how it differs from a spreadsheet. A page that answers only “we are the best accounting software” leaves those sub-questions to other sites, which are the ones an engine can cite.
Related terms
Google AI Mode is one place fan-out shows up in Search. Prompt tracking records the seed prompts you chose to repeat. Topical authority is the longer result of covering the cluster well, rather than one page aimed at one phrase.