Why it matters to a buyer
An AI Overview can answer the question before a searcher reaches the first organic result, so a page can hold its ranking and still receive fewer clicks. The flip side is that the links inside the overview are a new, prominent position a page can win. For a buyer, this changes what an agency should report: rankings alone no longer describe visibility on queries where an overview appears, so the report should say which of your target queries trigger one and whether you are cited in it.
How it is measured or applied
Google says pages need no special markup to be included; a page must be indexed and eligible to show a snippet. What helps is the same work that helps any extractable answer: a direct answer near the top of the page, clear headings, and content that adds something the other sources do not. AI Overviews traffic is reported inside the Search Console performance report together with ordinary web results, so measurement combines Search Console data with a tracked list of queries checked for whether an overview appears and which sites it cites.
