How do you choose a GEO agency?

Buying generative engine optimisation is harder to assess than a more established marketing discipline.

There is no accreditation, qualifying exam or professional register for GEO, and there is no agreed definition of exactly what the service should include. An agency can add an AI-search page to its website and start selling the work without having to meet an industry-wide standard.

That shows up in what agencies publish.

We read twenty UK agencies selling this service and scored each against the same seven criteria. Four publish no AI-search client work at all. Seven publish nothing a buyer could independently check, such as a figure without a named client, a percentage without a period or a case study about another service.

Six publish no price anywhere on their site.

Measurement is just as uneven. Six of the twenty explain what they measure, what they use to measure it and how often. Four state none of those things.

No agency in the study publishes a starting figure behind a percentage it quotes. That means the reported increase can be seen, but the starting point cannot be checked.

The information available on a website does not tell you everything about an agency’s ability. It does tell you what a prospective client can establish before making contact. That makes the questions below useful.

A percentage with no starting point is one of the most common problems.

An agency reporting a 300% rise in AI visibility may have moved a brand from one mention to four. Both figures describe the same change, but the second tells you much more about the scale.

Ask for the raw numbers, the date the baseline was taken and the prompt set used. No agency in our study publishes all three publicly.

A method with no named measurement tool is another.

An agency does not need to reveal proprietary processes, but you should be able to understand what is being measured and how. Seven agencies in the study name their measurement instrument publicly, which gives buyers something concrete to compare.

A price that only appears on a call is another common issue. Six of the twenty agencies publish no figure anywhere.

Quote-on-enquiry can make sense for genuinely bespoke work. It also means you have to enter a sales conversation before you know whether the budget is anywhere near the same order of magnitude as your other options.

The final warning sign is a promise of control over the answer itself.

An agency promising a fixed position, guaranteed mention or guaranteed inclusion in an AI answer should be able to explain how that guarantee works. AI answers are generated in response to individual prompts and can change between runs. The sensible focus is on improving the factors the agency can influence and measuring the resulting visibility.