Why this question matters more than ever in 2026
Generative Engine Optimization (GEO) and AI SEO are 2026's fastest-growing search disciplines. Gartner estimates 25% of all searches will run through AI assistants by year-end. Anyone not cited there loses visibility silently. Hundreds of agencies have added "AI SEO" to their service pages — only a few actually deliver. Here are the seven criteria that separate the specialists from the bandwagon.
Criterion 1: own AI visibility
Open ChatGPT (with web search), Perplexity and Google AI Overviews. Ask: "Which agencies for GEO and AI SEO do you recommend in DACH?" If the agency you are evaluating is never cited, the proof of practice is missing.
Criterion 2: technical understanding of llms.txt, ai.txt and WebMCP
The three current AI-visibility standards. Ask the agency which ones they implement by default and how they structure llms.txt for your industry. Vague answers mean GEO lives in the slide deck only.
Criterion 3: Schema.org depth
Implementations should include at minimum Organization, WebSite, BreadcrumbList, Service, Offer, FAQPage, HowTo, Article, LocalBusiness, GeoCoordinates, Person. Ask for examples and validate them with the Schema.org validator.
Criterion 4: content strategy for AI citability
AI models prefer content with clear factual statements, direct answers and identifiable authorship. A good agency explains passage-level citability scoring, the role of lists and tables, and how they build source authority.
Criterion 5: performance and Core Web Vitals
AI crawlers have limited budgets. Lighthouse 90+, LCP under 2.5 s, INP under 200 ms, CLS under 0.1, edge hosting and WebP/AVIF should be the default.
Criterion 6: measurement and AI visibility reporting
Brand citation rate, brand mentions in knowledge graphs, referral traffic from AI platforms, llms.txt crawl frequency. Agencies that answer with "SISTRIX" or "Ahrefs" miss the point.
Criterion 7: tech-stack depth
Next.js, React, TypeScript, headless CMS, custom MCP servers, edge hosting, relational databases. An agency offering "WordPress with a GEO plugin" cannot deliver serious GEO.
Bonus: fixed prices and transparency
A serious agency states what a GEO audit costs (EUR 1,500–4,500), an implementation (EUR 3,000–10,000) and ongoing support (EUR 500–1,500/month). Hourly rates without a service catalogue are a red flag.
