GEO vs AEO vs SEO: what each term actually means

The three terms, side by side

The nesting in the last row is the most useful thing on this page. GEO contains AEO, and both assume competent SEO underneath. They are layers rather than alternatives, which is why the vs framing in the title is slightly dishonest and why everyone uses it anyway.

Why the vocabulary is such a mess

Three reasons, all of them ordinary. The category is about three years old, so nobody had time to agree terms before the money arrived. Several vendors coined labels to own a phrase, which is a reasonable commercial move and a bad outcome for buyers. And the underlying technology changed twice while people were naming it.

You will also encounter LLM SEO, AI SEO, AI search optimisation, generative search optimisation and search everywhere optimisation. None of these describes work the three terms above do not already cover.

Which one you should be buying

Buy SEO if you do not rank

Google's AI surfaces are grounded in Google Search, AI Overviews are generated from pages already ranking, and Copilot runs on the Bing index. Without this foundation, nothing above it works.

Buy AEO if you rank but are not extracted

The symptom is stable rankings with falling clicks, and competitors appearing in overviews for queries you rank for. This is a content-structure problem and it is comparatively cheap to fix: start with how to rank in AI Overviews.

Buy GEO if you are absent from assistant answers entirely

Especially where the assistant is naming competitors without citing anyone. That is usually an entity and off-site citation problem, and no amount of on-site work will resolve it, which is what our generative engine optimisation service is built around.

Buy measurement regardless

You cannot tell which of the three you have without a baseline, and the baseline is cheap relative to guessing wrong for a quarter. Ours is free and yours to keep.

How to test a supplier on this

1. Ask which crawler controls whether you appear in ChatGPT citations. The answer is OAI-SearchBot, documented by OpenAI itself, and blocking GPTBot instead is the common error.
2. Ask whether their citation rate includes unlinked brand mentions. If it does, the number is roughly double what you think it is.
3. Ask which domains currently carry citations in your category. If they have not measured it, they are guessing at where the work belongs.
4. Ask what they would do if the answer is that you do not need them yet. A supplier with no version of that answer has one product. How to brief and evaluate a GEO partner has the full list.
5. Ask whether they sell llms.txt. The evidence says it does nothing, and selling it is a useful signal.

Frequently asked questions

Which term should we use internally?

Whichever your team will actually say out loud. We use AI search internally and GEO in writing. The important thing is that everyone means the same scope of work, which is worth ten minutes of agreeing at the start.

Is there a fourth term coming?

Almost certainly, and it will describe most of the same work. The underlying question, whether a machine that composes answers can find you, understand you and get you right, has been stable for three years while the labels churned.

Sources

1. OpenAI, overview of OpenAI crawlers. OpenAI's own documentation of GPTBot, OAI-SearchBot and ChatGPT-User.