Method 02 · AI search
Fan-out
mapping.
When someone asks Google's AI a question, it doesn't run one search. It runs a set of related ones behind the scenes, then builds the answer from the pages that cover them. Fan-out Mapping works out what those hidden searches are for your market, and checks whether your pages answer them.
Written by Dan Picken, founder. Last checked 27 October 2026.The question
best family car under $40k
- safest family cars australiaAnswered
- running costs per yearMissing
- 7 seats vs 5 seatsWeak
- resale value after 5 yearsMissing
- ANCAP rating explainedAnswered
- test drive near meWeak
Example. The AI builds its answer from the pages that cover these. Two missing means someone else gets quoted.
You optimised for
one search.
Google describes query fan-out as a set of related searches the AI model runs at the same time, to pull in more results than one search would. AI Mode launched in Australia in October 2025.
So a page built for one search can be invisible to the answer, because the AI also went looking for running costs, safety ratings and resale value, and found someone else's page for those.
Google also says no special files or markup are needed for its AI features. The way in is answering the follow-up questions well.
Google's VP of Product for Search, Robby Stein, described it plainly in a 2025 interview: for a question like planning a group trip, the system thinks of a bunch of related questions and starts searching for each, including things the person never asked.
How it
works.
- 1
Start with the real question
The questions your buyers actually ask, from Search Console, ads search terms, reviews and sales calls.
- 2
Map the fan-out
For each one, list the follow-up searches the AI is likely to run: costs, comparisons, risks, local options.
- 3
Check coverage
Which of those does your site answer clearly? Which does a competitor answer better?
- 4
Fill the gaps
Short, stand-alone sections that each answer one follow-up, so they can be quoted on their own.
Try it
How many follow-ups
does your page answer?
Type the main thing your page is about. You'll get the follow-up questions AI search tends to explore behind a question like it. Tick the ones your page clearly answers, each in its own section.
Google doesn't publish the exact searches it runs. These are the question types that come up again and again when the method is run on real topics.
Coverage
0/10
Tick what your page answers.
Answer next
A worked
example.
The question: 'is a heat pump hot water system worth it?'. Here's what a typical installer's page covers, against the follow-ups an AI is likely to explore.
| Follow-up the AI explores | Typical page | What would answer it |
|---|---|---|
| Running costs against gas and electric | Missing | A comparison by household size and tariff. |
| Upfront cost and rebates in NSW | One line about rebates | Who qualifies, roughly how much, and where to check. |
| Noise, and where to put it | Missing | Placement advice and what to ask the installer. |
| Cold-morning performance | Missing | How it copes on a cold Central Coast morning. |
| How long it lasts | Answered | Keep it, and add the warranty terms. |
| Who it doesn't suit | Missing | An honest list: small households, shaded spots, low hot water use. |
The page answered the main question. The follow-ups, where the decision actually happens, went to five other sites.
In my experience
Most sites I look at answer the main question well and stop there. The service page explains the service, but says nothing about cost, timing or what can go wrong, which are exactly the things the AI goes looking for next. Those gaps are where a competitor gets quoted instead of you.
When it's
not worth it.
- It won't make an unknown site an authority. Being quoted also depends on being trusted and mentioned elsewhere.
- Google doesn't publish the follow-up searches, so the map is an informed estimate, checked against People Also Ask, Search Console and the AI answers themselves.
- Not every follow-up deserves a section. Some only need a line.
What you get
- Your main buyer questions, from real data
- The fan-out searches behind each one
- A coverage map: answered, weak or missing
- The sections to add, page by page
- Before and after checks of how you appear in AI answers
The technical bit
- Query fan-out
- The extra related searches an AI runs behind one question.
- AI Overviews
- The AI summary at the top of some Google results.
- AI Mode
- Google's chat-style search, which leans hardest on fan-out.
- Passage
- A short section of a page that answers one thing on its own.
Where it's used
Questions
people ask.
Do I need an llms.txt file or special markup for AI search?
Google says no for its own AI features. Clear pages that answer the question and the follow-ups matter far more.
Can you guarantee I will appear in AI answers?
No. Nobody controls which sources the AI picks. What I can do is make sure your pages answer what it's looking for, and track whether you appear more often.
What is query fan-out?
When an AI search tool takes one question and runs several related searches behind the scenes, then builds its answer from the pages that cover them.
How do I find the follow-up questions for my topic?
Start with Google's 'People also ask' box and related searches, the long questions in your Search Console, and the sources cited in AI answers to your main question. The coverage check on this page gives you the common question types.
Does fan-out apply to ChatGPT as well?
ChatGPT also runs its own searches when it needs current information, sharing the question with search providers such as Bing. The same approach helps: answer the question and what people ask next.
How long should each answer be?
Long enough to answer properly, short enough to quote. Usually a short paragraph, a list or a small table under a clear heading.
The other methods
Want the whole market mapped, not just the top 3 fixes? See the Market Blueprint.
Want your market
mapped?
Takes a minute. Audits come back within 1 to 2 business days. For anything else, I'll get back to you as soon as possible.
What happens next
- 1I'll ask for read-only access, or just your website for a search audit.
- 2I go through it and write up the 3 biggest fixes.
- 3A 20-minute call to walk you through it. No pitch unless you ask.