How percentage pricing distorts advice
Under percentage pricing, every budget recommendation carries a conflict of interest. If the agency earns 15 percent of spend, advising you to scale from €10,000 to €20,000 per month raises its own revenue whether or not the extra €10,000 returns a profit for you.
The distortion is rarely dishonest and rarely visible. It shows up as optimism: marginal opportunities get framed as growth potential, and the case for cutting wasteful spend gets made a little less forcefully than the case for adding budget. The incentive does the work; nobody has to lie. Over a year, that quiet pressure can cost more than the fee itself.
Why a flat retainer is cleaner
A flat retainer removes the agency's stake in your budget decisions. The fee is the same whether you spend €5,000 or €15,000, so a recommendation to scale up has to stand on the data: marginal returns, impression share headroom, and conversion volume. A recommendation to cut spend costs the agency nothing, so it gets made when the numbers say so.
Etari Digitals uses flat retainers only, from €1,000 per month for Google Ads, precisely to keep budget advice free of conflict of interest. The advice and the invoice stay independent of each other.
Where percentage models still make sense
Percentage models have a legitimate place at very large scale, where spend levels genuinely drive workload. An account spending €200,000 per month across many markets and campaign types demands more management hours than one spending €20,000, and a percentage fee tracks that workload automatically.
For businesses spending under roughly €50,000 per month, a flat fee is cleaner. Whichever model you accept, demand the same discipline: spend recommendations backed by data, meaning marginal ROAS, impression share, and conversion volume, not enthusiasm. The pricing model shapes the incentives, but the data requirement is what keeps everyone honest.