The difference between SEO and GEO, also called GSO, lies first in measurement: rankings and clicks on one side, citations in the answers of generative AI on the other, on a shared technical and editorial foundation that serves as the bridge between the two. In March 2026, Ahrefs measured that only 38% of the pages cited in Google's AI overviews also appeared in the top 10 of classic results, against 76% in July 2025: a good Google ranking no longer guarantees a place in answers generated by artificial intelligence.
The facts
- In March 2026, only 38% of the pages cited in Google's AI Overviews also appeared in the top 10 of classic results, against 76% in July 2025; the rest is split almost evenly between positions 11 to 100 and beyond the hundredth (Ahrefs, 863,000 keywords analysed).
- According to an Ahrefs study published on 4 February 2026 on 300,000 keywords and Search Console data, queries where an AI overview is shown had a click-through rate of 1.6% on the first classic result in December 2025, against 3.9% for comparable queries without an overview, 58% less.
- An Ahrefs study of 75,000 brands, published in December 2025, finds an almost zero correlation, around 0.194, between the number of pages a site publishes and its visibility in generative AI answers.
Why are SEO and GSO not measured the same way?
SEO is measured in rankings and clicks, tracked on classic results pages. GSO is measured in citations observed in the answers of generative engines, ChatGPT, Gemini, Perplexity or Google's AI overviews, tracked month after month on a panel of queries replayed at a fixed cadence. The upstream mechanics differ too: being crawled by an AI query that tests several leads before answering, what the industry calls query fan-out, does not guarantee appearing in the final cited answer. A citation in an answer is not the same as a recommendation either: the first places a source in the generated text, the second explicitly names a company as the right choice.
The technical foundation remains common to both disciplines. Generative engines rely partly on the same signals as Google: clear content, consistent internal linking, clean structured data, authority built on the right topics through brand mentions and inbound links. Without these foundations, no GSO tactic holds over time. The near-zero correlation Ahrefs measured between page volume and AI visibility illustrates this shift: publishing more is no longer enough, and producing content that sets the reference on a precise topic becomes the priority, for ranking as much as for citation.
The bridges also lie in format and in measurement. Content already structured for SEO, with clear headings, lists and direct answers, becomes easier for generative engines to extract without any further substantive work. The difference sits in the tracking: a Google rank is read on a positions table, an AI citation is observed by replaying the same panel of queries at regular intervals. That is what changes for an agency, and what stays put: AIxH runs SEO and GSO as a single project, because this shared measurement only makes sense if the technical and editorial foundations are managed together.
AIxH's view
AIxH's SEO & GSO practice draws on search engine optimisation work that began in 1999, well before generative engines arrived, and on GSO work started with their first consumer versions. The two projects are handled as a whole, with the same team and the same tracking calendar: the technical structure and the extractable content are checked and then tracked over time, on the Google rankings we work on as an SEO agency in Luxembourg as much as on the citations recorded in the answers of generative engines, with tools that distinguish citation from recommendation. If your visibility in generative AI answers still needs building, a GSO audit is the entry point for building it.