Google's documentation on AI features says that "AI Overviews are only shown when our systems determine that it is additive to classic Search", and that a page is eligible when it is indexed and can be shown with a snippet. There is no opt-in and no markup that triggers one.
What we saw
On 2026-10-21 we fetched the Google results page for 25 buyer questions about AI visibility. An overview appeared for 22. The three questions without one were "Which search engine does ChatGPT use for web results?", "How many prompts should I track to measure AI visibility?" and "How does Perplexity choose which sources to cite?". Of three local questions the same day, the dentist in Austin got no overview; the accountant in Manchester and the plumber in Leeds got a local pack with Google ratings.
Where an overview did appear it cited 61 sources in total, 2.8 per question, and 16 of those were YouTube, LinkedIn or Reddit pages. No other assistant leaned on those three sites.
What to do
Before optimising a page for AI Overviews, check whether your buyers' questions trigger one at all. Search them, logged out, over a few days. If an overview appears, note what it cites: for our topic that was tutorials on YouTube and long posts on LinkedIn as often as articles. If none appears, the ranked results are what matter, and Google's AI Mode is a separate surface with its own behaviour.
A missing overview on a given day is not permanent. Google decides per query and per session, which is one more reason to re-check on a schedule rather than once.
