How Do ChatGPT, Perplexity and Google's AI Choose Which Businesses to Mention?
None of them publishes a full list of ranking factors. What they do publish is that ChatGPT ranks web results "using multiple factors intended to help users find relevant, reliable information", that Perplexity retrieves and re-ranks pages and parts of pages from its own index, and that Google's AI features draw on pages that are already eligible for Google Search.
ChatGPT
OpenAI's search help page gives site owners one concrete rule: allow OAI-SearchBot to crawl your site and make sure your host or content delivery network lets OpenAI's search crawler through. The same page says ChatGPT sometimes sends rewritten queries to other search providers, may use your approximate location for local results, and may share location with "trusted third-party providers" for things like nearby business listings. OpenAI does not name the listing providers.
For businesses that claim a profile, OpenAI's Business Hub help page adds that ChatGPT "may also use other sources when answering questions about your business", and that claiming does not guarantee increased visibility.
Perplexity
Perplexity's research post on its search system (September 25, 2025) is the most detailed public description we found from any of the three. It says the index tracks over 200 billion unique URLs, keeps documents "from authoritative domains" ready for fast retrieval, combines keyword and meaning-based retrieval, removes "clearly non-responsive or stale content", and then re-ranks results "at both the document and sub-document levels." Its crawler documentation says PerplexityBot surfaces and links websites in search results and is not used to collect content for AI model training.
Google AI Overviews, AI Mode and Gemini
Google's AI features documentation says there are no additional requirements or special optimizations to appear in AI Overviews or AI Mode: a page must be indexed and eligible to show a snippet in Google Search. It also says you do not need new machine-readable files or special schema markup.
What this means for a small business
- Be readable. If a tool's crawler is blocked by robots.txt or a firewall, your own site cannot be one of its sources. Check with our guide to whether your website is blocking AI search.
- Answer one question per section. Perplexity says it scores parts of pages on their own. A service page that answers "how much does it cost", "how long does it take" and "which areas do you cover" in separate, clear sections gives each answer a chance.
- Keep facts current and dated. Perplexity filters stale content, and OpenAI warns that results can be outdated.
- Keep your details the same everywhere. Both OpenAI and Perplexity draw on sources other than your own site, so your name, phone, address or service area should match on every listing.
- Do not buy promises. OpenAI says advertising does not influence ChatGPT's own answers. We found no paid or claim-your-listing route for a local business into Perplexity's answers.
What nobody knows from the outside
The weights, the exact sources for local business data, and how often answers change are not published by any of the three. Single test runs can mislead; if you track your business in AI answers, run the same question several times and record the sources cited. Our post on whether an AI mention sent a buyer covers how to measure it.
How Schkovl can help
We check crawler access, page structure and listing consistency as part of a Gap Analysis, and fix them through our SEO & Answer Engine Optimization work. Start here.