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Which sources AI search cites: GEO studies and the path to an enquiry

Which sources ChatGPT and Google's AI select, what GEO studies actually establish and how to measure visibility through to a qualified enquiry.

AI search selects sources according to the question, search process, model and available content. Relevant original information and independent reporting can fulfil different roles. Frequent citations establish neither general trust by the AI nor additional sales. For your business, the entire journey matters: being found, providing the right information and enabling a suitable enquiry.

Small business owners and marketing managers assessing the commercial value of visibility in ChatGPT and Google's AI.

Sources and context

What is established, and what are the limitations?

Study

GEO 2024: content changes the presentation of sources already supplied

The peer-reviewed paper tests text changes on 1,000 test questions from GEO-bench using Google sources and GPT-3.5. Supporting evidence, statistics and quotations improved visibility metrics by up to 40%.

Context: The sources had already been supplied. The additional Perplexity test also used uploaded source files, for 200 questions. Neither organic discoverability nor real clicks or purchases were measured.

Aggarwal et al.: GEO, KDD 2024, particularly Appendix C.1
Study

Toronto 2026: examine search selection and content separately

Two 90-day collections about US internet providers and B2B software contain 158,099 API answers. For ChatGPT, retrieval measures explained 32% of citation variation within a website; page features explained 2.8%. Additional controlled tests varied source order and brand names.

Context: Mostly associations, not a test of the effects of rebuilding a website. English US questions, small API models and search replays performed later limit generalisability. Consumer interfaces may behave differently; the paper is a preprint.

Chen and Koudas: What Drives AI Citations?, preprint of 10 October 2026
Study

SIGIR 2026: even Google's search systems select differently

The peer-reviewed study compares 11,500 questions across Google Search, AI Overviews and Gemini 2.5 Flash. Source lists collected in December 2025 differ substantially; common ownership does not mean identical source selection.

Context: A descriptive comparison at one point in time, mostly through APIs. The study does not isolate a single cause or examine ChatGPT, Bing Copilot or actual orders.

Grossman et al.: Google Search, Gemini and AI Overviews, SIGIR 2026
Manufacturer documentation

Google: established SEO fundamentals still apply

To appear as supporting links in AI Overviews and AI Mode, pages must be indexed and eligible for search snippets. Google requires neither special AI files nor special Schema.org markup for this.

Context: This describes Google's requirements, not an independent effectiveness study. Meeting them does not guarantee inclusion. The statement does not automatically apply to other platforms.

Google Search Central: AI features and your website
Manufacturer documentation

OpenAI: search access and model training are different settings

OAI-SearchBot serves search, while GPTBot serves potential model training. Website owners can control the two independently.

Context: Allowing access removes a potential access barrier. It does not promise a citation, recommendation or preferred placement.

OpenAI Docs: Overview of OpenAI Crawlers

Which sources are selected, and what does that mean?

A provider's current page may help answer a price question, an independent test may support a comparison, and original documentation may answer a technical question. What matters is which information addresses the specific task. A general league table of websites that every AI supposedly believes fails to reflect these differences. ChatGPT, Gemini, Google AI Overviews and Bing Copilot need to be considered separately.

From source selection to a business result
ObservationWhat it actually establishes
RetrievalThe system has fetched a page as a possible source.
CitationA source link appears in the answer.
Brand mentionThe company name appears; this need not be a recommendation.
ClickSomeone visits the linked website.
Qualified enquiryA contact fits the service, service area and prerequisites.
Paid orderA service has been commissioned and payment recorded.

These steps do not necessarily happen in full or in sequence. Someone may read your name and call later. Conversely, a source may be cited without its brand being recommended or its link being visited. Plan both the factual answer and an understandable route to contact.

What the studies contribute to your decision

The Toronto paper highlights a prerequisite that is often overlooked: content must reach the search selection in the first place. The reported explanatory shares are not forecasts of additional citations. Matching titles and paragraphs were relevant; FAQ blocks and Schema markup did not show a corresponding positive association within the same website. Equally, this does not mean a helpful FAQ section has no value for your customers.

Our practical inference: first invest in specific answers and verifiable information. Then check whether people and search systems can reach them. A short summary can help; a supposed formatting trick does not replace subject expertise.

Start with questions from real sales conversations

Collect recurring questions from calls, quotations and emails. Which uncertainty prevents an enquiry? Which information is repeatedly missing when you prepare a dependable quotation? Start with one service you actually sell and can deliver. This limits the work and makes subsequent evaluation meaningful.

  • Suitability: which customers and starting situations does the service fit?
  • Cost: which factors change the price, and what is included?
  • Comparison: when is an alternative more appropriate?
  • Preparation: which measurements, photos or documents are needed for a quotation?
  • Confidence: which projects of your own or verifiable qualifications demonstrate the work?

A possible planning example is a patio enquiry: a page explains ground conditions, material choices, the service area and the project photos required. It does not promise a blanket final price without a site visit. The next step is specific: send measurements and photos for an initial assessment. This is a content suggestion, not a reported customer success.

Publish verifiable content on accessible pages

Give each important buyer question a logical place: on the service page, in a comparison table or in a dedicated guide. Name the people responsible, cite sources and state when the information was actually checked. Link original evidence directly and describe its limits. Add genuine project images with approved details instead of interchangeable claims of success.

Check indexing, internal links, readable text and unintended access restrictions. Established SEO fundamentals remain relevant for Google. With OpenAI, search access and permission for training are separate decisions. Change crawler rules deliberately and check your hosting provider's settings too.

A specialist publication outside your website can also help customers assess their options: for example, a factual trade article or a transparent independent test. Choose such contacts for their audience and quality. Purchased mentions do not replace independent validation; publication does not guarantee inclusion in AI answers.

Measure answers, visits and enquiries separately

Record a baseline before making changes. Repeatedly check the same buyer questions in the relevant systems and record the date, mode, answer, brand mentioned and exact source URL. Also assess whether price, service scope and service area are represented correctly. A single favourable answer is not yet a stable finding.

Then record known referral visits and genuine form submissions. In conversation, invite customers to explain their first point of contact. In sales records, distinguish suitable enquiries, quotations, orders and payments. Missing source information remains unknown; it is not attributed to AI. Google includes search traffic from its AI features in Search Console's general Web report, rather than providing complete separate revenue measurement.

Start with a few important pages and an agreed review period. Compare the editorial work with suitable enquiries and the contribution margin earned. Record price changes, advertising and seasonality at the same time. With small numbers, a cautious assessment is more useful than an apparently precise GEO return on investment.

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For an existing website, you can commission our SEO service with a separately agreed scope. Ongoing SEO/GEO work, additional editorial content and repeated AI evaluations are outside the fixed Business Start package. Compare the offer and agree specific pages, buyer questions and measurement goals. A particular AI recommendation or additional orders are not guaranteed. View the SEO service and scope ↗

Your decision in practical steps

  1. Collected important buyer questions from actual conversations
  2. Prioritised a deliverable service and a suitable audience
  3. Published original evidence, limitations and the date checked
  4. Checked indexing, crawler access and the mobile enquiry process
  5. Documented AI answers across multiple runs
  6. Recorded qualified enquiries, orders and payments separately

Frequently asked questions

Does ChatGPT believe independent tests more than my website?

That cannot be promised generally. A test may answer comparison questions, while your website provides current prices and service terms. Citations show selection in a particular system and context. They measure neither general trust nor whether the content is factually correct.

Do I need a special AI file or special Schema markup?

Google requires no special AI files or special Schema.org markup for AI Overviews and AI Mode. First check the normal technical requirements and the visible content. Other platforms have their own access rules; these do not create a universal GEO shortcut.

Do more AI mentions establish commercial success?

No. Also evaluate known website visits, suitable enquiries and paid orders. Without an appropriate comparison, a change in those numbers is not evidence that AI visibility caused it.

Editorially reviewed on 25 October 2026. The studies examine different systems and periods. Our recommendations are practical inferences from them; they have not been tested as a Bissolux success study.

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