# How do I know whether an agency is any good?

**Short answer.** Call two clients the agency did not put forward itself, and ask about the time it went wrong. A portfolio shows someone at their best; a reference shows how they work when things go badly.

A portfolio shows someone at their best. What you want to know is how they work when things go badly, and that appears on no website.

## The reference that counts

Call two clients the agency **did not put forward itself**. You will find them on the factsheets, in the trade press, or simply by asking who still works for them. Then ask one question: what went wrong, and what happened next?

Every relationship longer than a year has had a moment where something broke. A client saying everything was always perfect either had a short relationship or has no wish to discuss it. The answer to that single question tells you more than ten slides of case studies.

## Three signals in the work itself

- **Different work for different clients.** An agency that makes five brands look alike is selling its own taste rather than your positioning.
- **Work that names a problem.** Ask what the assignment was for every case. Anyone who cannot answer that easily made the campaign without owning it.
- **Work that is still alive.** A campaign that ran for three years says more than one that won an award and then vanished.

## The number to know alongside

Median staff turnover in the Belgian agency market was 34.6 percent of headcount in financial year 2024. So about a third of the people change every year, and at a quarter of agencies more than two in three walk out the door.

That means "is this agency good" is a question about a team that will be partly different next year. So ask how long the people on your account have been there, and what happens if the most important of them leaves.

## What else you can check for free

The filed annual accounts say whether the agency covers its own operation, and the [factsheets](https://www.ikag.be/en/factsheets/) put those figures next to the market medians. See [how to know whether an agency is financially healthy](https://www.ikag.be/en/factsheets/faq/is-een-bureau-financieel-gezond) and [is an agency reliable to work with](https://www.ikag.be/en/factsheets/faq/is-een-bureau-betrouwbaar).

## Related questions

- [Is an agency reliable to work with?](https://www.ikag.be/en/factsheets/faq/is-een-bureau-betrouwbaar): Reliability is not a property of an agency but of a team, and teams turn over: in 2024 the median Belgian agency lost 34.6 percent of its staff. So ask who stays, not whether the agency is good.
- [Which criteria do I use to compare agencies?](https://www.ikag.be/en/factsheets/faq/criteria-om-bureaus-te-vergelijken): Five axes are enough: the work, the team you actually get, the fit with your sector and your way of working, the price per unit of work, and the stability of the business. Weight them before you see the first presentation.
- [What do I ask in a first meeting with an agency?](https://www.ikag.be/en/factsheets/faq/eerste-gesprek-met-een-bureau): Three questions surface the most: who works on my account day to day, what share of your revenue is your largest client, and which brief did you turn down this year. The third answer tells you the most.

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IKAg is the business consultant for marketing and agencies in Belgium and the Netherlands. Market figures come from the Agency Barometer, calculated on the annual accounts agencies filed with the National Bank themselves. Figures on pitches and satisfaction come from IKAg-guided processes, and are always presented as such.

- All questions: https://www.ikag.be/en/factsheets/faq
- Last updated: 2026-08-19