Short answers.

One question per page, answered first and explained second. Where a number comes from our own check, the page says what was run and when. Where nobody knows yet, it says that. 22 questions so far; the longer guides and measured reports are on the blog.

Getting recommended by ChatGPT

Where ChatGPT gets its answers about businesses, and what you can and cannot do about them.

• Which search engine does ChatGPT use for web results?

  Its own index, crawled by OAI-SearchBot, plus Bing, which OpenAI names as its third-party search provider. Two single-page tests showed ChatGPT citing a page only Google could see, so Google results reach it in some cases as well.

• Does ChatGPT recommend local businesses, and how does it pick them?

  Yes. Asked for an accountant in Manchester, a dentist in Austin and a plumber in Leeds on 2026-10-21, ChatGPT named specific businesses every time and took the ratings and review counts from directories: Clutch, Healthgrades, Zocdoc and Checkatrade. Claude declined all three questions.

• Is there a ChatGPT business listing I can add my business to?

  No. There is no ChatGPT profile to claim. OpenAI only accepts product feeds from merchants for shopping results. For a service or local business, ChatGPT reads what the directories, review sites and your own website say, so those are what you keep accurate.

• ChatGPT has facts about my business wrong. What fixes it?

  You cannot edit a ChatGPT answer. You can change what it reads: the directory or review page it quoted, and your own site. Answers made with search on pick up a page change within days. Answers made from training data change only with the next model.

• How often does ChatGPT update what it knows about my business?

  Two clocks run. With search on, ChatGPT reads pages at answer time, so a change on a page it cites can show up as soon as it is re-crawled, usually within days. What the model knows without searching comes from training and changes only when OpenAI ships a new model.

• Can I submit my website to ChatGPT or Perplexity?

  No. Neither OpenAI nor Perplexity has a submission form. OpenAI builds its index with OAI-SearchBot and uses Bing as its search provider, so the nearest thing to submitting is Bing Webmaster Tools and IndexNow. Perplexity asks only that you allow PerplexityBot.

What the assistants cite

Counted from the same 25 buyer questions on five assistants, so the answers carry a date.

• Which AI assistant cites small websites most?

  Perplexity, by a wide margin. Across 25 buyer questions on 2026-10-21 it cited 250 sources from 187 domains, most of them small marketing and consultancy sites. ChatGPT cited 47, and 43 of those were OpenAI, Google or Perplexity documentation.

• Do AI assistants cite LinkedIn posts?

  Sometimes, and mostly in Google AI Overviews. In our 25-question check LinkedIn posts and articles were cited 9 times across 7 questions: 6 by AI Overviews, 2 by Perplexity, 1 by Claude. ChatGPT and Gemini cited none.

• Do AI assistants cite YouTube videos?

  Google AI Overviews does. The others did not in our check. YouTube videos were cited 7 times across 25 buyer questions on 2026-10-21, all 7 by AI Overviews, on 7 different questions. ChatGPT, Perplexity, Gemini and Claude cited no YouTube link.

• Do AI assistants cite Reddit threads?

  Less than you may have read. In our 25-question check on 2026-10-21, Reddit threads were cited 3 times, all by Google AI Overviews. Perplexity, with 250 citations in the same run, cited none. A Trustpilot-commissioned study of 804,491 responses put user-generated content at 5% of citations.

• Do AI assistants read G2, Capterra and Trustpilot when they recommend software?

  Yes, and more the closer the question is to a purchase. For local service questions on 2026-10-21, ChatGPT and Perplexity cited Healthgrades, Zocdoc, Checkatrade and Which? Trusted Traders. A Trustpilot-commissioned study of 804,491 AI responses found review sites were 14% of citations overall and 24% for purchase questions.

• Does Google show an AI Overview for every question?

  No. Google says an AI Overview appears only when its systems judge it adds something to the normal results. In our check on 2026-10-21, 3 of 25 buyer questions and 1 of 3 local questions came back with no overview.

• Does schema markup get a page cited by AI assistants?

  Not on the evidence so far. Ahrefs tested 1,885 pages that added JSON-LD and found no meaningful citation increase in AI Overviews, AI Mode or ChatGPT. Google says no special markup is needed for its AI features. Keep schema accurate, but do not expect it to move citations.

Crawlers, robots.txt and files

What each bot does, what blocking it changes, and which files matter.

• GPTBot, OAI-SearchBot and ChatGPT-User: which one decides whether ChatGPT cites me?

  OAI-SearchBot. It builds the index ChatGPT search answers from, and blocking it removes your site from search answers within about a day. GPTBot only governs training data. ChatGPT-User fetches a page when a user asks for it and plays no part in deciding what appears in search.

• Does blocking AI crawlers hurt my Google rankings?

  No. Google reads only Googlebot's rules, so blocking GPTBot, ClaudeBot or PerplexityBot changes nothing in Google Search. Blocking Google-Extended does not either: Google says it is not a ranking signal and does not affect inclusion. The one block that removes you from Google's AI features is blocking Googlebot itself.

• What is llms-full.txt, and do I need one?

  llms-full.txt is a convention from documentation platforms: one plain-text file with the full text of every page, served next to the llms.txt index. The llms.txt proposal does not define it, and no AI provider has said it reads either file. Anthropic's docs serve one of 46 MB and Mintlify's is 1.6 MB, both read on 2026-10-21.

• How long until a new page shows up in ChatGPT or Perplexity answers?

  Days, if the assistant searches the web for the question; the next model release, if it answers from memory. Perplexity says changes register within 24 hours, and OpenAI says the same for crawler settings, but the page then has to be retrieved and chosen. Nobody publishes a guaranteed time.

Measuring AI visibility

Free checks, sample sizes and what shows up in your analytics.

• Is there a free way to check my AI visibility?

  Yes, three. Ask the assistants yourself in fresh sessions and write down who they name. Use Semrush's or Ahrefs' free checkers for a one-off snapshot by domain or brand. Or run Seen42's free check of 10 prompts you choose on ChatGPT and Gemini, which shows who was named and cited.

• How many prompts do I need before a change means anything?

  More than one run of any number. Assistants answer the same prompt differently from one run to the next, so one check of ten prompts cannot tell a real change from noise. Track a fixed set of 10 to 20 prompts weekly, read the trend over four to six checks, and keep two or three control prompts you do nothing for.

• What is utm_source=chatgpt.com in my analytics?

  The tag ChatGPT has added to links in its answers, so analytics can see the click came from ChatGPT. In our API check on 2026-10-21 every one of ChatGPT's 47 citations carried utm_source=openai. A report from 14 October 2026 says the consumer app stopped adding the tag and the referrer, so some ChatGPT visits now show as Direct.

The basics

Two terms that come up on every other page here.

• What is AI search, and what is an answer engine?

  AI search is a search whose result is a written answer instead of a list of links. The system runs web searches, reads the pages, and writes a reply that names a few sources. An answer engine is a product that does this: Perplexity, ChatGPT with search on, Google's AI Overviews and AI Mode, Gemini, and Claude with web search.

• What is an answer page?

  A page built to answer one question a buyer asks an AI assistant: the question as the title, the answer in the first paragraph, the facts and sources under it. Comparison pages, facts pages and short guides are the common kinds. This page is one.