GEO vs SEO: what actually changes when buyers ask an AI

Search used to end with a list of ten links. Increasingly it ends with a paragraph written by a model, and your brand is either inside that paragraph or it is not. That shift is why generative engine optimisation (GEO) has become a separate discipline from search engine optimisation (SEO), even though the two share most of their foundations.

What stays the same

Crawlability, speed and clear structure still matter. If a page cannot be fetched and rendered, no engine, generative or otherwise, can use it. Topical authority still matters: engines prefer sources that cover a subject thoroughly and consistently. Links and mentions still matter, because they are one of the main ways an engine decides which sources are worth trusting.

What changes

The unit of competition is the answer, not the page. A blue link wins by being the best page for a query. A citation wins by containing the clearest, most extractable answer to a specific prompt. That rewards direct statements, defined terms, short evidence-backed paragraphs and tables over long introductions.

Prompts are longer and more specific than keywords. People ask “which CRM suits a 20-person services firm that invoices in two countries” rather than “best CRM”. Prompt research replaces keyword research as the starting point, and the long tail becomes the whole tail.

Consistency across the web counts. Engines reconcile what your site, review platforms, communities and press say about you. If your pricing page says one thing and a Reddit thread says another, the answer may reflect the thread.

Measurement has to be built. There is no Search Console for ChatGPT. You need a defined prompt set, a schedule for running it across engines, and a log of which brands are cited. We track prompts monthly across ChatGPT, Perplexity, Gemini and Google AI Overviews and report the changes next to organic traffic and enquiries.

A practical starting point

1. Write down the twenty questions a buyer asks before choosing you. Phrase them as a person would type them.
2. Run them through four engines and record who is cited. That is your baseline.
3. For each question you are missing from, find or create the page that should answer it, and make the first 150 words answer it directly.
4. Fix the inconsistencies between your site and the sources engines cite.
5. Re-run the prompt set monthly.

GEO is not a replacement for SEO. It is the same work, judged by a different referee. The teams that win treat it as one programme, with one set of pages serving both.