The most important criteria for choosing an SEO agency are:
- Real case studies: can the agency show concrete client results (with data, not just testimonials)? Watch out for vague cases or cases without metrics.
- Clear methodology: does the agency have a structured method or does it just improvise? A documented method signals maturity and predictability.
- Transparency: do you have access to the data and reports? Can you see what is being done month by month? Agencies that hide data are a risk.
- Full scope: does the agency do technical SEO, content and link building, or only one of those? Effective SEO needs all three.
- GEO included: in 2026, an SEO agency that completely ignores generative AIs is behind the curve.
One more important point: be suspicious of guaranteed results ("position 1 in 30 days"). No serious agency controls Google's algorithm. What a good agency does guarantee is process, transparency and technical expertise.