Every time search changes, somebody invents a new acronym and announces that everything you knew is wrong. AEO. GEO. LLMO. Each one arrives with a new service line and a new invoice.
They are not three separate religions. They are layers of the same job.
AEO vs SEO: where the agency expertise is the same
AEO and SEO agency expertise is the same where it counts most: getting pages crawled, indexed and ranked. An answer engine that searches the web can only cite what a search index already holds. People will tell you nobody knows how the engines pick their sources. Except we do. Google says it plainly about its own AI features:
"There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary."
So an AEO agency with no SEO skill is a house with no foundation. Nice brochure, though.
AEO vs SEO: the differences in what an agency has to know
The differences between AEO and SEO in what an agency has to know come down to a short list. Our editor, David Quaid, writes it as GEO = SEO + QFO, and it still holds if you swap the first letter.
| Area | SEO expertise | What AEO adds |
|---|---|---|
| Research | The queries people type | Query fan-out (QFO): the related searches the engine runs on the user's behalf |
| Authority | Links from pages that rank | Being named on the third-party pages the engines cite: lists, reviews, directories, forums |
| Reporting | Rankings, clicks, conversions | Citations, grounding queries and share of the answers, on a fixed set of prompts |
| Content | Pages that match the query | The same pages. Google says you don't need to rewrite content for AI systems |
| Technical | Crawlable and indexable | The same, plus checking that AI crawlers aren't blocked at the firewall |
Look at the right-hand column again. Two of the five rows say "the same".
The AEO expertise most SEO agencies still lack
The AEO expertise most SEO agencies still lack is measurement. An SEO report counts clicks. An AI answer that names you and sends nobody to your site is invisible in that report. So the agency needs a second set of numbers: how often you are cited, for which grounding queries, and against whom.
It is not standard yet. Of the 345 providers eligible for an EliteAEO ranking, 195 say on their own sites that they report AI visibility to clients. 30 say they do not. The other 120 don't say.
The second gap is source work. In our September 2026 AI Visibility Index, 226 of 358 AI answers cited a "best agencies" list and 90 cited a directory or marketplace. The engines lean on pages you don't own, so somebody at the agency has to do PR. Old-fashioned, pick-up-the-phone PR.
How to test an agency's AEO and SEO expertise
To test an agency's AEO and SEO expertise, ask four questions and see which ones get answered without a slide.
- Who does the technical SEO, and who builds the links?
- What are the grounding queries for one of your clients in Bing Webmaster Tools?
- Which third-party pages do the engines cite in my category?
- Can I see last month's report for a client, with the prompts in it?
An SEO agency can answer the first one. An AEO agency can answer all four. A firm that can only answer the last three is a reporting tool with a sales team.
If you are comparing firms now, our guide to choosing an AEO agency has the full set of checks, and the methodology shows how we score specialization and proof. The dataset figures come from the State of the AEO Agency Market 2026.