Why Your Agency's "% of Spend" Pricing Model Is the Reason You Aren't Profitable
Your agency charges 15% of ad spend. You spend £50k/month, they earn £7,500. You spend £100k/month, they earn £15,000. Their revenue doubles when your spend doubles. Whether your profit doubles, halves, or disappears is irrelevant to their bank account.
This is not a criticism of individual account managers. Most of them genuinely want to do good work. This is a statement about incentive structures. When the system rewards budget growth rather than profit growth, the system will optimise for budget growth.
Percentage of spend is the industry standard for a reason: it scales with client size and appears to align interests ("bigger client = more work = more fee"). But the incentive alignment is an illusion.
The Conflict in Numbers
Let us examine two scenarios at a 15% fee rate:
Scenario A: Efficient Spend
Scenario B: Bloated Spend
In Scenario B, you made less profit but the agency made more. Their fee doubled while your profit more than halved. This is not malice. This is arithmetic.
The Subtle Budget Creep
Most agencies do not explicitly advocate for unprofitable spend. They advocate for "testing", "opportunity capture", "competitive defence", and "market share". All of which sound reasonable. All of which increase spend. The question that is rarely asked: does this incremental spend generate incremental profit?
The Behaviours This Model Encourages
When agencies are paid more for spending more, certain behaviours become rational even if they are not in your interest:
1. "Opportunity" Framing
Every budget increase is framed as an opportunity: "We're leaving money on the table." "Competitors are outspending us." "We could capture more share." The framing is always toward more spend, never toward efficiency.
2. Resistance to Cuts
When performance drops, the recommendation is rarely "let's spend less until we fix this." It is usually "let's maintain spend while we optimise" or "let's test new approaches (with additional budget)."
3. ROAS Instead of Profit Focus
Reporting centres on ROAS because it justifies spend.POAS (Profit on Ad Spend) is rarely discussed because it might reveal that incremental spend is unprofitable.
4. Complexity Inflation
More campaigns, more testing, more segments. Complexity justifies the fee and creates dependency. Whether complexity improves outcomes is secondary to whether it appears to require expertise.
Alternative Models That Actually Align
The percentage-of-spend model is not the only option. Alternatives exist that better align agency and client interests:
Pricing Models Compared
Agency earns the same regardless of spend. This removes the incentive to inflate budgets but also removes skin in the game for performance.
Base fee plus bonus tied to profit metrics. Aligns interests without creating budget inflation incentives.
Agency earns more when you profit more. Rare because it requires access to margin data and genuine partnership.
Percentage applies up to a cap. Beyond the cap, additional spend has no fee impact, removing incentive for endless budget growth.
How to Protect Yourself Within % of Spend
If you are locked into percentage-of-spend pricing, you can still protect your interests:
- Gate budget increases with profitability thresholds.No additional spend unlocks unless current spend meets profit targets.
- Demand marginal performance reporting. Every budget increase must show the marginal return on that specific increment, not blended averages.
- Require profit-based reporting. Insist on seeing contribution margin, not just ROAS. If they cannot report on profit, they are not thinking about profit.
- Set hard spend caps. Define maximum spend levels that cannot be exceeded without explicit board or finance approval.
The percentage-of-spend model is not inherently evil. It is a legacy of an industry that grew up when spend was harder to track and profit was impossible to attribute. But in an era of granular data and sophisticated measurement, it is an outdated model that creates systematic misalignment between agencies and the businesses they serve.
The Honest Conversation
The next time your agency recommends a budget increase, ask them this: "What is the marginal profit we will generate from this additional spend? How do you know?"
If they can answer with data and specificity, you have a good partner who thinks about your business. If the answer is vague ("more reach", "competitive pressure", "testing opportunities"), you are getting advice that benefits their revenue more than yours.
Work With a Partner Whose Incentives Match Yours
JudeLuxe operates on fixed-fee pricing with performance transparency. We earn the same whether you spend £30k or £100k. Our advice is based on your profit, not our fee.
Discuss a Different Model