SEO, AEO, GEO and “SEO 3.0”: what do the new names mean for a small business?

SEO, search engine optimisation, is the oldest of the three. It is the work of getting a page into a search engine’s index and high in the list of links it shows. The reader still picks a link and visits your site to find out more.

AEO, answer engine optimisation, is about being the answer rather than one link in ten. The term is usually applied to the answer boxes at the top of results, which Google calls featured snippets, and to voice assistants that read a single reply aloud. Google says its systems decide for themselves whether a page makes a good featured snippet, and that no markup can request one.

GEO, generative engine optimisation, takes its name from a 2023 research paper. It is about assistants that write a fresh answer from several sources, such as ChatGPT search, Perplexity, Microsoft Copilot and Google’s AI Overviews, and its aim is for your page to be one of the sources they draw on and cite.

“SEO 3.0” is not a standard. Agencies use it as an umbrella for everything above, and some add layers and trademarks of their own. When someone offers it, ask which of the three they mean and what they will actually change on your site.

The biggest change is where the reading happens. A list of links sends a reader to your page to make up their own mind. A written answer does part of that reading for them, so the question is whether your facts reach the answer intact, and not only whether your page ranks.

An answer is also assembled from more than one page. A generative engine lifts passages from several sources and combines them, which is how the GEO paper describes the systems it studied. A sentence from your site can end up beside one from a directory or a competitor, so a vague sentence is easy to misquote and a precise one is hard to get wrong.

And there is more than one engine. ChatGPT, Perplexity, Bing and Google each run crawlers and systems of their own, and a robots.txt rule that turns one of them away takes you out of that one alone. The guide to AI crawlers on this site lists which name does what.

The companies that publish advice say much the same thing. Google’s guide to its generative AI features calls the work search engine optimisation, with no separate discipline and no special files. Microsoft’s advice of October 2025 on AI search answers talks about being selected, not only found, and says its systems look at sections of a page and judge how clearly each one answers a question.

Put together, that is a familiar list. The page has to be open to crawlers and in the index. Each section should answer one question in plain words, early in that section. The facts should agree with what other sites say about you. None of it is new, and all of it helps people as much as machines.

So AEO and GEO are best read as a sharper focus on parts of SEO rather than a replacement for it. Google says its AI features draw on the same index as its ordinary results, and OpenAI says ChatGPT sends its searches to search providers, so a page that search cannot read has little chance in either.

The paper that gave GEO its name was written by researchers at Princeton and elsewhere and presented at the KDD conference in 2024. The authors built a benchmark of test questions and measured how much of each source’s wording made it into generated answers, and how prominently, after its text had been rewritten in different ways.

Its abstract reports that the right changes can boost a source’s visibility in generated answers, measured that way, by up to 40%, and that what works varies between subject areas. The changes that helped most added quotations, statistics and citations of sources. Keyword stuffing, the old trick of repeating search terms, did poorly by comparison.

Two cautions before anyone sells you something on the strength of that figure. It was measured in a research setting, not on the live assistants your customers use today, and those systems change often. For a small business the useful lesson is a plain one: specific facts that a reader can check are easier to quote than vague claims.

Good work under any of these names looks like ordinary work done carefully: clearer pages, accurate listings, structured data that matches the page, and a way of checking results. The warning signs are the ones SEO always had, with new words attached.

Ask what will change on your site and elsewhere, how they will measure it, and what happens if nothing moves. A clear answer to all three is a good sign. Be wary of any of the following.

Start with what customers already ask you: what you do, where, your prices or how you price, your opening hours and how to book. Give each its own short section that answers the question in its first sentence. A café in Tenby is better served by a section that opens “We’re open every day from 9 till 4, and dogs are welcome” than by a gallery of cakes. If you trade in Welsh and English, do it in both.

Then check the basics every engine shares, and ask the assistants yourself once a month, reading the sources they cite as well as the answer. The free assessment on this site reads one address and shows what a machine can and cannot find there.