How to Choose an AEO & GEO Services Company

Google's documentation says a page only has to be indexed and eligible for a snippet to appear as a supporting link in AI Overviews or AI Mode — no additional technical requirements, no specific optimization ([ev-ai-search-agency-selection-01]). Jeremy Moser, CEO of uSERP, told Digiday that 80% of GEO is good fundamental SEO, and a service that does not say so openly is selling snake oil (Digiday, 2026; [ev-ai-search-agency-selection-03]).

Generative Engine Optimization (GEO) is real work, but the cited subset depends on the same fundamentals plus a few. A vendor who can say that in one sentence is worth a meeting; one who cannot has repackaged AI Impact on SEO under a new logo. Modern SEO sets out the shift those fundamentals have to absorb; What Is Generative Engine Optimization? GEO Guide (2026) covers the mechanism. This page covers the purchase.

A defensible proposal names four levers. Agencies lead with the first; the fourth decides the contract.

1. Access. Are the AI crawlers you want allowed in? A blanket block on AI bots in robots.txt is a common self-inflicted citation wound, fixed in AI Crawl Control and your own rules.
2. Extractability. Does a page state a clear answer near the top in clean HTML, so a system can lift it? The AI Search Visibility Audit check most worth paying for.
3. Authority and corroboration. Named expertise, sourced claims, consistent entity data — the E-E-A-T Standards layer assistants weigh.
4. Measurement. A repeatable sample with dates and a documented method rather than a dashboard — the lever that most often gets its own line item, and the one most often sold as a screenshot.

A proposal that leads with levers one and two and cannot describe lever four is selling content production, not strategy.

A usable first baseline can be built for free before anyone pitches you.

• Search Console Performance. Google folds traffic from Google AI Overview and AI Mode into the ordinary Performance report under Web, not broken out separately ([ev-ai-search-agency-selection-02]). To read AI characteristics at all, open the separate mid-2026 generative AI report: it carries impressions only — no clicks, CTR, queries or position ([ev-ai-search-agency-selection-11]).
• Referral data. ChatGPT appends a utm_source=chatgpt.com parameter to outbound links, so AI-referred sessions are separable in your analytics ([ev-ai-search-agency-selection-11]).
• The robots.txt line. OpenAI states that sites opting out of OAI-SearchBot are not shown in ChatGPT search answers ([ev-ai-search-agency-selection-11]).

Published estimates of AI-referred traffic span roughly twentyfold — a fraction of a percent of search referrals at one end, one agency panel above 6% of sessions at the other — and most come from companies selling AI search services (Business.com, 2026; [ev-ai-search-agency-selection-10]). The >6% figure is that one panel, not a threshold to test a quote against. Similarweb data cited by Digiday puts publishers most mentioned in ChatGPT and Perplexity under 1% of traffic from those platforms (Digiday, 2026; [ev-ai-search-agency-selection-06]).

The prompt-set specification. Write into the contract a jointly defined set of 20 to 50 questions real buyers ask an assistant, run across several engines on a fixed schedule, recording which businesses are cited and from which sources ([ev-ai-search-agency-selection-14]). Jointly defined is the operative phrase: your questions, not the vendor's. The contract only has to name them, the engines, and whether you get the raw sample. A vendor who answers "we'll monitor AI Overviews" is not measuring; it is observing.

Why share of voice is not measurement. Most AI-visibility tools never see the prompts real users type; they infer surfaced brands from synthetic prompts and data modelling ([ev-ai-search-agency-selection-04]). With no stable LLM ranking to sit on ([ev-ai-search-agency-selection-05]), nobody can promise a placement.

The demand case, and its click cost. Forrester's Buyers' Journey Survey 2025 found business buyers using AI in their buying process rose five points to 94% (Forrester, 2025; [ev-ai-search-agency-selection-16]). A randomized field experiment with 1,065 US participants found outbound organic clicks fell 39.8% and zero-click searches rose 34.5% when an AI Overview appeared (Business.com, 2026; [ev-ai-search-agency-selection-09]). That is a shift in Impressions vs Clicks — a citation layer over informational queries — so Search Intent Matching decides where the work goes.

The metric that survives a CFO. AI-referred sessions are small but convert well: the Washington Post's chief revenue officer reports AI-referred visitors convert subscriptions four to five times better than search traffic ([ev-ai-search-agency-selection-06]). That is why vendor ROI claims are hard to falsify. Demand sessions, leads, and revenue segmented by referrer, with your own conversion rate applied, as SEO ROI asks. Traffic Estimation with Similarweb is the one cross-check here you can run yourself, and the only one with a source attached — though it estimates a panel, not your own traffic.

One published vendor pricing page puts the band at a $99 one-off audit, $590–$1,990 per month for SMB retainers, $2,000–$3,500 per month for managed campaigns, and $10,000–$50,000+ per month at the enterprise end — while noting most agencies publish no prices at all (vendor pricing page, 2026; [ev-ai-search-agency-selection-13]). Treat it as a published band, not a market average: its existence partly proves its own point about opacity.

• Fixed-price audit. Bounded scope, easiest to compare, a poor retainer — the work stops when the invoice does. Run findings through the SEO Audit Template with severity and effort.
• Monthly retainer. The default. Ask what changes at month six; a retainer renewing on identical deliverables has bought a calendar slot.
• Project with an end date. A content rebuild, a schema programme, a citation-recovery push. The SEO Project Plan Template is the instrument.

Anchor the GEO line item to the SEO retainer: ask what it buys that is not already there, and make the answer survive Price Anchoring both ways. Cost-Based vs Value-Based Pricing is the split underneath — a named deliverable is cost-plus; citations you cannot guarantee are a value claim not yet earned.

WebFX and Evolve both flag five ([ev-ai-search-agency-selection-15]): guaranteed rankings or citations; a methodology that cannot be explained in plain language; a pitch that never mentions SEO foundations; over-focus on a single AI platform; and reporting that stops at visibility. Two more sit alongside: a team roster you have never met, and mass-generated Reddit comments as content seeding ([ev-ai-search-agency-selection-15]).

The sharpest red flag is a deliverable list that contradicts the fundamentals. Google's May 2026 AI-search guidance still calls generative-AI optimisation SEO, and rules llms.txt files, content chunking, AI-specific rewrites and special schema unnecessary ([ev-ai-search-agency-selection-08]). What Is Generative Engine Optimization? GEO Guide (2026) sets out that platform-owner position in full, including the Machine-Readable Files for AI question. A proposal built on a bespoke rewrite pass or an assistant schema layer is a rebrand.

This is the narrower procurement question: whether the discipline is worth a separate vendor.

Four circumstances justify a separate AI search retainer ([ev-ai-search-agency-selection-12]):

1. You have no search function at all. No owner, no baseline, no fundamentals. You are buying a foundation and should price it like one.
2. You have real technical debt, scoped as a defined-end project. "Thousands of URLs, half of them thin" is scoped work. "Improve our AI presence" is not.
3. You operate in a regulated or high-liability category where an assistant misstating your pricing or credentials is a compliance exposure. Contract for accuracy verification specifically.
4. Your unit economics support it. A customer worth tens of thousands of dollars justifies a few thousand a month; a few-hundred-dollar sale does not ([ev-ai-search-agency-selection-12]). Run the Customer Lifetime Value (LTV) arithmetic before the pitch.

The same guidance says replace an agency that cannot answer basic AI search questions rather than adding a second one ([ev-ai-search-agency-selection-12]): two retainers produce contradictory recommendations and a blame split that ends with you owning neither. The cheapest fix is the one nobody sells — the robots.txt block costing you citations today.

Eight questions sort a credible vendor from a rebadged retainer:

1. What percentage of this work is standard SEO, and what is genuinely new? ([ev-ai-search-agency-selection-03])
2. Show me the exact 20 to 50 questions you will run. Who wrote them? ([ev-ai-search-agency-selection-14])
3. Which engines, on what schedule, and do we get the raw sample or only your summary? ([ev-ai-search-agency-selection-14])
4. What sits in the report besides visibility — sessions, leads, revenue by referrer? ([ev-ai-search-agency-selection-06])
5. What will you not do, and why? ([ev-ai-search-agency-selection-08])
6. Do any of your deliverables conflict with Google's own AI-search guidance? ([ev-ai-search-agency-selection-01], [ev-ai-search-agency-selection-08])
7. Who is on the account team, and which of them have I met? ([ev-ai-search-agency-selection-15])
8. What is the monthly figure, the minimum term, and the exit clause?

How much does an AEO/GEO agency cost?

One vendor pricing page publishes a band and notes most agencies publish nothing. Test a quote against it, not against a market rate.

Should I do this in-house or hire an agency?

Mostly in-house: access is a one-line robots.txt change, measurement is a query set you run yourself, extractability is ordinary on-page rewriting. Buy outside help when you have no search owner, defined technical debt, or a compliance exposure.

How long before an agency retainer shows results?

Nobody can put a result date in a contract: answers are regenerated on every request and no stable ranking exists to wait on ([ev-ai-search-agency-selection-05]). Ask instead for a baseline, a fixed re-run schedule and a defined end date — commitments a vendor can be held to.

What should the contract actually say?

Name the prompt set, the engines, the schedule, who wrote the questions, and whether you get the raw sample. If those are missing you are buying screenshots.

• What Is Generative Engine Optimization? GEO Guide (2026) — the mechanism behind the pitch
• SEO for SaaS Agencies — the seller-side view
• SEO Audit Template — the deliverable format to demand
• SEO Project Plan Template — structure a fixed-end project
• SEO ROI — pricing an unprovable channel honestly
• Modern SEO — what changed when answers moved above results

• Google Search Central — AI features and your website (official, 2025). (accessed 2026-09-29, ev-ai-search-agency-selection-01, ev-ai-search-agency-selection-02)
• Digiday — GEO hype busted (2026). (accessed 2026-09-29, ev-ai-search-agency-selection-03, ev-ai-search-agency-selection-04, ev-ai-search-agency-selection-05, ev-ai-search-agency-selection-06)
• Business.com — Should You Hire an AI SEO Agency? (2026). (accessed 2026-09-29, ev-ai-search-agency-selection-08, ev-ai-search-agency-selection-09, ev-ai-search-agency-selection-10, ev-ai-search-agency-selection-11, ev-ai-search-agency-selection-12)
• generativeengineoptimization.solutions — GEO Agency Pricing 2026 (vendor pricing page, low confidence). (accessed 2026-09-29, ev-ai-search-agency-selection-13)
• Evolve — Top 10 AEO & AI Search Optimization Agencies in USA (2026, vendor buyer guide, low confidence). (accessed 2026-09-29, ev-ai-search-agency-selection-14)
• WebFX — How to Choose a GEO Agency (2026, vendor buyer guide, low confidence). (accessed 2026-09-29, ev-ai-search-agency-selection-15)
• Forrester — B2B Buyers Make Zero-Click Buying Number One (2026). (accessed 2026-09-29, ev-ai-search-agency-selection-16)
• How we research, source, and correct these guides: XKnow research standards

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