GEO, AEO, ACO: the category taxonomy

The AI search optimization category has three competing names: GEO, AEO, and ACO. Each came from a different team with a different bet on where the puck is going. This page defines all three, lays out where eCommerce Insights sits, and explains why we use the neutral term "product AI visibility" on product pages.

The three names

Three teams coined three terms within about eighteen months. The terms describe overlapping things. The differences matter mostly when you are writing copy for two audiences (a buyer and a search engine) at once.

GEO — Generative Engine Optimization

What it is. The discipline of getting brand and product content cited by generative AI search engines: ChatGPT, Perplexity, Google AI Overviews, Gemini, Claude.

What it covers. Source trust (does the engine treat your domain as authoritative), retrieval grounding (can the engine ground its answer in your content), structured data (does your schema map cleanly to the engine's product model), and content shape (does your PDP answer the question the user is asking the engine).

Where it shines. GEO is the most general of the three terms and the most-searched. Use it when writing for SEO-aware audiences. It is the umbrella the other two fit under.

AEO — Answer Engine Optimization

What it is. Optimising for the answer surface specifically, as opposed to the broader generative ecosystem. Answer-engine pages return one synthesised answer, not a list of links.

The naming fork. Most of the industry uses AEO to mean Answer Engine Optimization. A small enterprise-vendor camp uses AEO to mean Agent Engine Optimization, arguing it better describes a world where AI agents (not just answer engines) consume content. We define both in the glossary; in copy, we default to the industry-standard expansion.

Where it shines. AEO is the most descriptively accurate term for what D2C brands are actually doing — they are trying to be the cited source inside an answer. Use it when the audience is hands-on SEO and you want to be specific.

ACO — Agentic Commerce Optimization

What it is. Optimising for autonomous agents that don't just answer questions but make purchases on behalf of users. ChatGPT Operator, Perplexity Pro Buy, the still-emerging agentic-commerce category.

Coiner. An enterprise vendor in the agentic-commerce space. The term has not yet escaped that vendor's marketing.

Where it shines. ACO is the most forward-looking framing. If the audience already believes agentic commerce will be material in two years, ACO is the cleanest label for the practice. If the audience is still in the answer-engine phase, ACO sounds like it skips a step.

eCommerce Insights's stance

Three rules of thumb.

1. Define all three neutrally in the glossary. Buyers searching for any of the three acronyms should land on a eCommerce Insights glossary entry that gives them the honest definition.
2. Lead with neutral, descriptive language on product pages. "Product AI visibility" and "SKU-level AEO" are the two wedge terms used on product pages. They describe the thing without picking a side in the taxonomy war.
3. Rank for category terms in long-form content. Long-form guides target GEO, AEO, and ACO independently — see What is GEO, What is AEO, and What is ACO.

Practical implications for buyers

If a vendor tells you they "do GEO," ask which engines, which scoring buckets, and whether their measurement is at SKU level or brand level. If they "do AEO," ask the same plus whether they handle the agent variant or the answer-engine variant. If they "do ACO," ask which agents specifically — ChatGPT Operator, Perplexity Pro Buy, or something else — and what their measurement loop looks like for purchases that complete inside the agent.

The terminology is a signal of where a vendor thinks the puck is going. The practice is the same.

Common questions