Choosing a GEO agency: What to compare before hiring a consultant

Ask AI, "Which provider should I choose for GEO consulting?" and it returns a list of five or six provider names. The list changes slightly each time you query it, and when you search the names, the websites sound so similar that you cannot choose from the list alone. Comparing consulting deliverables instead of names is faster. Check item by item how a proposal includes the prompt list, baseline figures, citation source analysis, site configuration diagnosis, roadmap and raw data.

For a month starting in late June 2026, PION submitted the same question to ChatGPT and Gemini 46 times. Counting every source cited in the answers, there were 551 cited URLs, and 88% of the sources cited in ChatGPT answers were sites operated directly by agencies or tool vendors.

1. How does AI pick GEO agencies for its answers?

It reads the pages that providers wrote themselves and builds a list. Across the 46 measurements, ChatGPT attached sources to 29 of its 30 answers, with an average of 13.1 URLs per answer. Of those sources, 88.2% were agencies' and tool vendors' own sites. Community posts accounted for just 8.2%, and media articles for 2.6%. The single domain cited most often was an overseas community, but it accounted for only 24 of 380 citations.

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

Even with the same question, 89 domains appear in rotation, and 31 of them show up once and then disappear. If a GEO agency is recommended often, that means pages about the agency appear often in search. It is weak evidence of consulting quality.

The answers named 16 providers. The most frequently named appeared in 20 of the 46 answers, and the next in 18. In 11 answers, none of those 16 names appeared; the answers explained only provider types and how to choose.

2. Why over half the citations are overseas sites

AI also uses English search terms for Korean-language questions. ChatGPT searched with the original prompt text in all 30 cases, adding Korean and English search terms such as the Korean query "GEO consulting provider generative engine optimization Korea" and the English "GEO consulting agency Korea Seoul". As a result, Korean domains made up 38.3% of the 551 cited URLs: 33.9% for ChatGPT alone and 48.0% for Gemini.

That is why questions about Korean GEO agencies bring in many overseas agency directories and English-language pages introducing tools. If an unfamiliar English provider name appears in your candidate list, first ask whether it offers service in Korea.

Under the same conditions, PION's own page was cited once out of 551, and its name never appeared in an answer's body.

3. How to compare consulting deliverables

What to compare in a proposal is the form of the deliverables, more than the list of case studies. Case study lists look similar in every proposal, but deliverables are either defined in writing or not.

Compare the prompt list and baseline figures first. If you do not write these two into the contract, the agency will choose the questions that go into the performance report three months later. The items to ask about when signing a contract are covered in GEO agency recommendations: Why AI answers change and how to choose.

4. What happens during a 4-week consulting engagement

PION's GEO consulting is 4 weeks by default, with the work for each week set in advance.

The schedule is adjusted to 2–6 weeks depending on site size. The deliverables are the site configuration and SEO baseline diagnosis report, the GEO diagnosis report, and the improvement priority roadmap and execution guide. The raw measurement data is delivered together as JSON and tables, so the client can cross-check the report's figures directly. The detailed diagnosis procedure is explained in What is an outsourced AI visibility audit, and how does it work?.

5. Warning signs in a proposal

A proposal that touts keyword density as a performance metric conflicts with verified evidence. The research paper that first formalized generative engine optimization compared optimization methods on a 10,000-query benchmark.

• Citing sources, adding statistics and inserting quotations: 30–40% higher visibility in answers
• Adding keywords: little to no improvement
• A page ranked 5th in search that cited sources: visibility up 115.1%
• A 1st-ranked page under the same conditions: visibility down 30.3%

If a proposal contains any of the following, ask for the evidence.

• AI-only files or markup offered as a paid item. In its AI features documentation, Google explicitly stated that there are no additional requirements or special schema for appearing in AI Overviews and AI Mode.
• Phrases that guarantee exposure on an engine. As shown above, even the most-cited domain's share does not exceed 10%.
• A proposal that only lists case studies without measurement. Without baseline figures, there is nothing to compare against three months later.
• Keyword density or backlink counts used as KPIs. The earlier study found almost no improvement from this approach.

6. Which fits you, consulting or outsourcing?

If you have someone in-house to write content, consulting is enough. PION also offers consulting limited to the strategy and design stages. In that case, your internal team or existing agency handles implementation, and PION provides a more detailed execution guide.

If you lack staff to publish, or drafts keep piling up while publishing falls behind, move to outsourcing that covers diagnosis, publishing and monitoring together.

What an outsourcing contract does and does not cover is laid out in Generative engine optimization: What can you outsource?. If you are in a Korean industry that requires prior advertising review, such as healthcare, also check GEO services for hospitals and clinics: Working within medical advertising rules. How to choose based on your internal staff is covered in What kind of GEO consulting suits an early-stage startup?.

You can review what each service includes in the GEO consulting service guide and the managed GEO service overview.