Key points
- SEO consultant Cyrus Shepard opted Zyppy SEO out of Google's AI features from Sept. 1 to Sept. 29, then compared 28-day periods.
- He estimates AI Overviews and AI Mode drove about 21% of the site's search clicks, or 23% counting a halo lift on regular listings.
- AI features were about 10% of impressions, with an estimated 0.9% click-through rate versus roughly 0.4% across Google Search for the site.
- The UK's CMA gives Google until Dec. 3 to give publishers AI feature impressions, clicks and click-through rate.
Why it matters for marketers: Opting out of AI features may cost more traffic than impression data suggests, and Google's reports do not yet split AI clicks out, so marketers must estimate.
Cyrus Shepard, founder of Zyppy SEO, used Search Console's generative AI control to exclude his site from AI Overviews and AI Mode for four weeks, then opted back in. By comparing the opted-out period with the following 28 days, he estimated that AI features produced about 21% of the site's Google search clicks. Adding a small lift he sees on regular listings, he puts the share at 23%.
The gap between impressions and clicks is the notable part. AI features made up about 10% of the site's search impressions, but he estimated a click-through rate of about 0.9% on them, against roughly 0.4% for Google Search overall. Shepard describes the regular-listing lift as a halo effect, with brand reinforcement as a likely explanation, though he says nobody knows for sure.
Shepard calls this a single experiment on a single site, a "directional yardstick" rather than a rule, and other sites could land higher or lower. He also notes Zyppy has worked to earn AI citations, which may inflate its share. Still, for marketers weighing an opt-out, the test shows that impression share alone may understate what is at stake.
The measurement problem remains. Google counts clicks on AI links as ordinary clicks in the Performance report, and its documentation does not describe a way to separate them. The UK's Competition and Markets Authority has given Google until Dec. 3 to give publishers impressions, clicks and click-through rate for AI features, aggregated across them. Teams with UK traffic should watch for that data before deciding on any opt-out.
Sources
This brief is our own summary. Read the full reporting at the source.