Where the term comes from
Google used the phrase when it rolled out AI Mode in the US on May 20, 2025: AI Mode breaks a question into subtopics and issues many queries at once on the searcher's behalf. Google's documentation says AI Overviews and AI Mode may both use it, and that its Deep Search feature takes the same technique further, with hundreds of searches.
Why it matters for SEO
In a normal search, one query decides which pages can appear. With fan-out, the answer draws on pages that match any of the sub-searches, and Google says this lets it show a wider and more varied set of links than a classic search. A page that answers one narrow follow-up question clearly has a way into answers it would never rank for on its own.
How to plan for it
Treat each main search as the start of a list, not a single target:
- Write down the follow-up questions a buyer asks after the first search.
- Check that one page on your site answers each of them, in its own section.
- Give each answer a heading that says the question and a first sentence that answers it.
- Skip a new page for every phrasing; one page per question is enough.