| Different AI engines cite largely non-overlapping sources |
Even the closest pair (Perplexity and Google AI Overviews) overlaps on only about 23.7% of domains; the most divergent pair (ChatGPT and Gemini) shares about 11.9% |
Writesonic, Jul 2026 161,286 prompts |
| Ranking on Google is not the same as being cited by AI |
Only about 12% of pages cited by AI assistants also rank in Google's top 10 for the same question; around 80% of cited pages are not in the top 10 at all |
Ahrefs, 2025 15,000 long-tail questions |
| Google's own AI Overviews are the exception |
About 76% of the URLs cited in Google AI Overviews come from Google's top 10 results |
Ahrefs related study |
| Most citations come from sources a brand neither owns nor pays for |
About 84%–94% of AI citations come from sources the brand does not own or pay for |
Muck Rack Generative Pulse |
| Verified, structured data is cited independently more often |
Verified and structured data accounts for 54.53% of independent citation sources |
Yext, 2026 17.2 million citations |
| AI favours encyclopedic, news and government sources, and cross-engine visibility is inconsistent |
Wikipedia, news media and government sites are cited far above their share of traditional search results; being cited on ChatGPT does not mean Gemini or Claude treats the brand the same 3 source classes carry the heaviest citation weight, and their rankings differ between engines. |
University of Toronto, 2026 cross-engine source study |
| A single test is noise, not signal |
Re-running the same question on the same day can vary by up to 38%; drift rates are about 40.5% for Perplexity and 59.3% for Google AI Overviews |
Public industry reporting, 2026 |