ChatGPT and Gemini visibility: What to handle in-house and when to hire a GEO agency

Ask, "Can you recommend a place that will make my company show up in ChatGPT and Gemini search?" and you get a to-do list instead of a vendor list. AI treats the question as a how-to question and offers about five steps of guidance, such as checking robots.txt, using question-style titles and adding an FAQ. You can handle crawler access and page format in-house right away by following this guidance, while repeated measurement per engine and external mentions are work for a GEO agency.

Over a month starting in late June 2026, PION put this question to ChatGPT and Gemini 44 times. Only 10 vendors and tools were named in the answers, and in 33 of the 44 runs the answer explained methods only, without any of those names. Even the most frequently mentioned vendor appeared just 5 times, and in 40 of the 44 runs the answer gave action items you can carry out yourself, such as robots.txt, schema, FAQ and llms.txt.

1. Why AI responds with methods instead of vendors

AI answered using documents that explain methods as its sources, rather than pages introducing vendors. Of ChatGPT's 28 answers, 17 cited sources, while the remaining 11 answered from its own knowledge without a web search. In the answers that cited sources, the most-cited domain was a paper repository, at 18 of 254 citations; it hosts the paper that first formalized generative engine optimization. Gemini frequently cited a video platform and Google Search Central documentation.

(PION measurement, 2026-06-21 to 07-21)

ChatGPT used English queries such as "AI search optimization agencies GEO AEO" and "llms.txt generative engine optimization vendors." As a result, the citation list contains many pages from overseas tools and agencies, and the share of Korean domains is low. For a Korean vendor to be named in the answer to this question, it needs pages that answer the phrases AI actually searches for.

2. Can you handle crawler access and indexing in-house?

One developer can complete the robots.txt check, the first step suggested in AI answers, within a day. According to the OpenAI crawler documentation, OAI-SearchBot, used for search, and GPTBot, used for training, are configured separately. A site that blocks OAI-SearchBot will not appear in ChatGPT search answers, and if you want to opt out of training, you only need to block GPTBot. The same document notes that after you change robots.txt, it takes about 24 hours for the change to be reflected in search results.

In its AI features documentation, Google explicitly states that there are no additional requirements to appear in AI Overviews and AI Mode. You do not need a new machine-readable file or special schema; you just apply the same SEO fundamentals as regular search. The llms.txt that AI answers recommend is optional by Google's standard.

Check indexing status in Google Search Console and Bing Webmaster Tools. If a page is not indexed, none of the page work in the next section will have any effect.

3. Page format improvements you can handle in-house

This work creates paragraphs that AI can carry over into its answers in full. Most of the 44 answers commonly advised rewriting titles into question form, answering that question directly in the first paragraph, and placing the FAQ in a separate section.

The evidence is the 10,000-query benchmark in the research paper mentioned above.

• Citing sources, adding statistics and inserting quotations: 30–40% higher visibility in answers
• Adding keywords: little to no improvement
• Pages around fifth place in search that cited sources: visibility up 115.1%
• A first-place page under the same conditions: visibility down 30.3%

The lower a site ranks in search, the greater the effect of this work. Page design methods are covered item by item in Content formats and design principles that increase AI search citations. An in-house content owner can handle the work up to converting existing pages that open with an introductory paragraph into a format that answers directly in the first paragraph.

4. Repeated measurement and external mentions to hand to a GEO agency

Repeated measurement involves too much volume to do by hand. The 44 measurements in this article are figures for a single prompt. Measuring 30 to 80 brand-category questions the same way for each engine means recording and classifying thousands of responses per month. Of the 117 unique domains ChatGPT cited for this question, 66 appeared only once, so the result of asking once depends on chance.

Work on your own site cannot replace external mentions. As shown in GEO agency recommendations: Why AI answers change and how to choose, the sources AI picks up first for recommendation-type questions are pieces written by third parties. Increasing brand mentions in communities, media outlets and Q&A platforms has to proceed separately from fixing your own pages.

5. How does it work if you hand it to PION?

PION's managed GEO service proceeds in this order: question selection, repeated measurement, content publishing and applying results. In the question selection stage, we map prompts for each brand, and in the repeated measurement stage, we measure responses across four engines (ChatGPT, Gemini, Google AI Overviews and AI Mode) to establish the baseline figures. Based on those results, we produce content that includes FAQs, direct answers under H2 headings, clearly identified entities and schema markup, and publish it on a domain your brand owns. External PR and contributed articles are also available as add-ons.

Performance is tracked by the rate at which your pages are cited as sources in AI answers, the change in share relative to the baseline, AI referrer traffic, external channel mentions and indexing metrics. When published content shows up in AI answers, and how much the answers change, depends on the industry and the question. Choose GEO measurement if you only want to receive the measurement results and review them in-house, or managed GEO if you want to outsource the work through publishing. You can find the details in the managed GEO service overview.