AI recommendations draw mostly on directories, listings and businesses' own websites, but each engine leans on different sources. The studies discussed here come from Nimza, 8ight and Yext. All sell AI visibility services or software. Read their findings as directional evidence for what to inspect, with close attention to the cities and fields each study covered. A citation list does not explain every reason a practice gets named.
The short answer: listings and your own site
Start with the profiles used in your field, then check your own website. There is no single directory list in these studies that fits every dentist, med spa and law firm. A source that appears often for personal injury lawyers is not evidence about dental searches.
Yext, which sells listings and AI visibility software, counted 155.5 million citations across 1,623 brands and four AI models for questions with location on, from January to March 2026. It found that 80% pointed to a brand website or a listing. MapQuest led third-party domains with 6.0 million citations, followed by TripAdvisor at 3.8 million and Yelp at 2.1 million. These are brand findings, not a study of practices specifically. See Yext's location-based citation research.
The practical takeaway is to review both your site and outside profiles. Do not treat that broad ranking as a spending list for your practice.
What the studies found by type of business
The field-specific lists below come from Nimza's October 2026 edition of What ChatGPT, Perplexity, Gemini and Claude cite for local searches. Nimza sells AI visibility services. It counted 7,336 citations across four engines, 615 cities and 31 trades, from answers dated September 15 to October 19, 2026. Its dental sample is especially narrow.
| Business | Sites cited most | Study and sample |
|---|---|---|
| Dentists | phoenixmag.com, thephoenixreview.com, healthgrades.com, zocdoc.com, localpicks.ai, dental.me | Nimza: 1 city only, Phoenix |
| Med spas | medspascout.com, portraitcare.com, yelp.com, fresha.com, yellowpages.com, trustanalytica.org | Nimza: 49 cities |
| Personal injury lawyers | justia.com, attorneys.superlawyers.com, avvo.com, lawyers.findlaw.com, bestlawyers.com, profiles.superlawyers.com | Nimza: 230 cities |
Use these names as places to inspect. The dental findings do not establish a national pattern, and the lawyer list covers personal injury searches. Before paying for a profile, check whether that source appears for your field and city. The table does not show that buying a listing causes a recommendation.
Each engine reads differently
Nimza reported 2.7 citations per ChatGPT answer, 19.6 for Perplexity, 1.8 for Gemini and 2.5 for Claude. In its tests, Gemini alone read Google Maps, reviews and Google Business Profile information; the other engines did not cite Google Maps or Google reviews. It describes that sample, not a permanent rule about access. See Nimza's engine comparison.
8ight, which sells AI visibility services, published Ask an AI for a roofer on October 5, 2026. Its 1,630 answers included 1,412 from ChatGPT and 218 from Claude. Asked September 10 to 30, 2026, the questions covered 39 trades in 49 places in the US and Greater Toronto Area and 2,976 businesses from Google Maps. ChatGPT cited the Better Business Bureau in 38.7% of answers and government or licensing sites in 25.1%. Claude cited Yelp in 92.7%. The sample included med spas, but no other health care and no law.
Check the source links in each engine you care about. A result from ChatGPT does not tell you what Claude cites. Our ChatGPT and Google local search guide offers more context for comparing searches.
Reviews help, but do not decide the list
8ight also found that ChatGPT named 3.4% of businesses with under 25 Google reviews and 22.2% of those with 1,000 or more. Yet the most reviewed business checked in a place was named just 22.8% of the time. The median star rating was 4.9 for both named and unnamed businesses. See 8ight's review findings.
More reviews were associated with more mentions in that sample. The study does not establish that the reviews caused those mentions. Nor does it give dentists or lawyers a review target, since neither field was included. For a med spa, treat review counts as context alongside the cited profiles, rather than a threshold that earns a place.
The lists change between checks
In 8ight's data, ChatGPT got the same question twice, a median 39 minutes apart. A median 29% of the businesses named in either answer appeared in both. See 8ight's repeated-question findings.
That is a reason to keep a record before judging a change. Save the question, engine, date, location setting, businesses named and sources cited. If your practice disappears from a later answer, check again before tying it to a recent website edit. The study shows variation; it does not explain the cause of every changed list.
What to do this month
Use the findings to make a focused review list. Begin with facts you can verify and errors you can fix.
- Inspect the profiles for your field. Start with the table, then compare it with citations for your own city and services. Do not assume every listed site deserves a paid account.
- Make the facts match. Compare your practice name, address, phone, hours and services across your site and profiles. Ask for corrections where details are wrong.
- Put services and cities in plain page text. State what you offer and where patients or clients can find you. Keep those details easy to read without relying on an image.
- Check licensing records. Review the public details that apply to your practice and request corrections when needed. This follows the government and licensing source finding in 8ight's study; it is not a claim about a legal duty. Check legal questions with your own counsel.
- Check each engine separately. Keep a separate record of its answers and citations. Do not use another engine's source list as a substitute.
- Treat each check as a sample. Repeat comparable questions before drawing conclusions. Record inaccurate details as well as missing mentions.
For more on applying this to a local business, read how to show up in ChatGPT as a local business.
Who did these studies?
Nimza and 8ight sell AI visibility services. Yext sells listings and AI visibility software. All have a commercial interest in the subject. Read their research as directional evidence, with its stated limits.
Nimza separates fields and engines, but its dental coverage is limited to Phoenix. 8ight covers home services, fitness and med spas, with no law or other health care. Yext counts citations for brands with location on. These are different samples, so do not add their percentages together or treat them as a shared ranking of directories.
How WTM handles it
WTM Studio quotes SEO, including AI search work, per project. That work is available on any site, including sites WTM did not build. There is no published SEO price or monthly fee.
The written 180-day full refund guarantee is about new patients or leads, not rankings or AI mentions. For SEO, the period starts when the first SEO changes go live. If the work brings no new patients or leads during that period, the guarantee provides a full refund. A lead is a contact form, phone call or booking from the website.
Questions about the sites AI cites
Which sites does ChatGPT cite for dentists?
Nimza reported Healthgrades for every ChatGPT dental citation in its Phoenix sample, with answers dated September 15 to October 19, 2026. That is one city only, not a national dental finding; see the Nimza study.
Which sites do AI engines cite for med spas?
Nimza lists medspascout.com, portraitcare.com, Yelp, Fresha, Yellow Pages and trustanalytica.org among its med spa sources. Use its field findings as a starting point for checking your city, rather than a fixed list for every engine.
Which sites do AI engines cite for lawyers?
For personal injury searches, Nimza lists Justia, Super Lawyers, Avvo, FindLaw and Best Lawyers domains. Nimza's reported list covers personal injury searches only and should not be read as evidence for every area of law.
Who did these studies?
Nimza and 8ight sell AI visibility services, while Yext sells listings and AI visibility software. Their studies cover different samples, so treat them as directional.
Do more Google reviews get my practice named by ChatGPT?
More reviews were associated with more mentions in 8ight's study, but that does not prove cause or promise inclusion. Its sample included med spas but no dentists or lawyers.
Why does AI give a different list each time?
The cited research does not explain every changed answer. 8ight found changes even when it repeated the same question, so keep records across checks before judging a pattern.