AI SEO × Retainer Work
AI SEO Agencies for Retainer Clients (September 2026)
AI SEO agencies with verified retainer client evidence — ranked by depth of documented work, then editorial quality.
Each listed agency documents retainer engagements on its own site or in a published case study; the model is never inferred from a service list.
Ranked AI SEO agencies for retainer clients
Rankings updated · Newest review
Redkiwi
#1Rotterdam, Netherlands
Client evidence: 9 documented clients overall
Best for: Dutch consumer brands and B2B suppliers buying a website, webshop or campaign where generative AI speeds up content production.
Found
#2London, United Kingdom
Client evidence: 8 documented clients overall
Best for: UK consumer brands in retail, insurance and hospitality that want AI applied inside paid search, SEO and campaign data.
London, United Kingdom
Client evidence: 6 documented clients overall
Best for: UK online retailers that want an existing SEO campaign extended to how ChatGPT, Gemini and Perplexity recommend brands.
NOVOS
#4London, United Kingdom
Client evidence: 5 documented clients overall
Best for: Consumer e-commerce brands that want to be named in AI answers through SEO and digital PR, with share-of-answer tracking.
Graz, Austria
Client evidence: 3 documented clients overall
Best for: B2B and industrial firms that want to be named in AI answers and will fund a measured, ongoing program.
About this list
The AI SEO retainers documented here are visibility campaigns and measurement programs rather than systems, and they differ in how far their figures can be checked. NOVOS reports a sharp number: Osprey's share of AI answers in its category rose 21.4 points in twelve months to 72.6%; Heal's three-month digital PR campaign produced 23 pieces of coverage and 20 links from 18 domains aimed at publications LLMs cite. The study does not say which assistants, prompts or tracking tool produced the share figure, and NOVOS retainers are priced against its own Signal score. ClickSlice publishes before-and-after shares across ChatGPT, Gemini, Perplexity, Copilot and Google AI Overviews for named clients, National Private Investigators' visibility rising from 3.9% to 30.6%, though no case dates the campaign, names the tracking tool or publishes the prompt set. wukonig.com publishes its method in more detail than its outcomes: a fixed question set repeated across ChatGPT, Gemini, Perplexity and Google AI Overviews, scored on mention rate and cited sources, with ams OSRAM listed as ongoing advisory and no result published. Redkiwi's SEO evidence is conventional: Verder Liquids' 168% rise in quote requests came through the BrightEdge platform, and a card reading 'Advertising in ChatGPT' sits on a case describing Magento and Google campaigns.
A visibility retainer is only as good as the baseline it is measured against, so fix the question set, the assistants and the tracking tool in the contract. Ask NOVOS what an independent share-of-answer target would look like beside its Signal score; ask wukonig.com for a before-and-after on a named question set, since its published engagements are training and advisory; ask Redkiwi which parts of the scope touch AI answers at all. Working language matters here too, since wukonig.com publishes in German only.
Intro by Gabor Kiss, curator · How we rank
Expert Insight
Why retainer fit matters for AI SEO
Deployed AI degrades without an operator: models drift, prompts age and source data changes shape, so the question is not whether someone maintains the system but who, at what price and against which metrics.
A documented retainer is evidence the agency has run a system past launch, which a portfolio of delivered builds cannot show.
Continuity and dependency look identical in month one; the exit terms, ownership of pipelines and evaluation sets, and published operating metrics tell them apart.
Frequently asked questions
5 agencies in our directory combine verified retainer client evidence with documented AI SEO work. The current top-ranked are Redkiwi, Found, ClickSlice — ordered by depth of documented client evidence, then our editorial scoring (portfolio quality, credibility, completeness); placement is never paid.
Published rates across this page's agencies run €85–170 per hour (median ~€129). Project totals depend on scope — the rate index at /rates breaks the computed bands down by region, country and team size.
Every agency here documents retainer work on its own site or in a published case study, describing the engagement structure rather than a service-list claim. We never infer the model from portfolio tone, so this list only contains agencies that operate retainer engagements deliberately.