Search has split into three surfaces, and each now has its own acronym. If you run a business, the jargon can make it hard to decide what to fund. Here is the plain-English version.
The three layers
SEO — Search Engine Optimization. Earning high positions in Google and Bing's organic results and the local map pack. It is still where most commercial clicks happen.
AIO / AEO — AI (Answer Engine) Optimization. Getting your content cited in AI-generated summaries that sit on the search page, such as Google's AI Overviews.
GEO — Generative Engine Optimization. Getting your brand named and recommended inside conversational AI assistants like ChatGPT, Gemini, Perplexity and Copilot.
Side-by-side
| SEO | AIO / AEO | GEO | |
|---|---|---|---|
| Where it shows | Search results & maps | AI summary on the search page | AI chat assistants |
| What you win | A ranking and a click | A citation in the answer | A mention or recommendation |
| Built on | Site quality, relevance, links | Strong SEO + answer-first content | Strong SEO + entity + off-site reputation |
| Typical buyer stage | Research to purchase | Early research | Research and shortlisting |
| How to measure | Rankings, traffic, leads | Overview citations, branded search | Share of AI voice, mentions |
They are not competitors
The most important point: these layers stack. AI Overviews tend to cite pages that already rank. AI assistants that browse the web retrieve pages that search engines have indexed and trust. A brand with weak SEO will struggle at AIO and GEO too.
Think of it as a pyramid:
- Foundation — technical SEO and local SEO. Crawlable site, fast pages, accurate business listings, clear service pages.
- Middle — content and authority. Answer-first content, reviews, links and mentions from credible sites.
- Top — AI visibility. Optimizing that authority so AI systems extract it, cite it and recommend you.
How to split your budget
There is no universal ratio, but these rules of thumb hold up:
- If your site has technical problems or thin service pages, spend most of the effort on SEO fundamentals first. Nothing above it works without this.
- If you already rank well, shift effort toward answer-first content and schema to capture AI Overview citations.
- If you sell a considered, high-ticket service (assisted living, med-spa, B2B services, home systems), invest in GEO early — buyers increasingly ask assistants for shortlists before they call anyone.
- If you are e-commerce, prioritize product-page SEO, reviews and comparison content; these feed both AI Overviews and shopping recommendations in assistants.
Questions to ask any agency
- How will you measure visibility inside AI answers, not just rankings?
- What will you change on our website versus off-site?
- How do you tie this work to leads and revenue?
- What does month one look like, specifically?
If the answers are vague, the strategy probably is too.
The bottom line
SEO gets you found. AIO gets you quoted. GEO gets you recommended. A modern search strategy does all three, in that order.
Not sure which layer is holding your business back? Book a strategy call and we will show you where you stand on each.