About Kesterley
Work you can inspect.
Kesterley is a research and advisory firm. We measure what AI assistants such as ChatGPT, Gemini and Claude tell buyers about companies and markets, and help leadership teams decide what to do about it. Research first, then business judgement, then the agreed work.
Founder
Martin Drab
Fifteen years on the strategy side of marketing. He co-founded and leads Grizzlink, a strategy and communications agency, and Meat & Friends, an investment vehicle that builds marketing operations into early-stage companies. Before Grizzlink he ran his first agency, Digistory, and earlier worked at Publicis Groupe. Along the way he built the AI stack that runs his agency’s daily operations, which is where the question behind Kesterley came from: what do these systems actually tell our clients’ customers?
He holds a master’s degree in media and communication from Charles University in Prague, studied marketing at HKBU in Hong Kong, and completed Mark Ritson’s Mini MBA in Marketing.
Kesterley is based in Prague, working with clients globally.
Where the method comes from
From marketing science: brands grow through mental and physical availability across the situations in which buyers enter a category. Kesterley applies that framework to machines and calls the result AI availability. The buying situations become the questions we put to AI assistants; the answers become the measure.
How we work
Fixed scope, fixed price, written findings. The audit ends in a report your team can act on the same week. The Program turns the findings into a growth strategy and sees it through with you, built on our own AI measurement. We work with CEOs, founders and marketing and sales leaders, and with agencies under their own brand.
Why the numbers can be trusted
Designs frozen before measurement, our own reliability disclosed, and a public, versioned methodology. When a difference is within noise, we say so. We take no money from AI vendors or from the brands in our public reports, and we never sell placement in AI answers.
See how we work
The fastest ways to judge us: run the free check on the homepage, read an industry report, or read the methodology itself.