How to choose a performance marketing agency.
We are an agency telling you how to shop for agencies. The conflict of interest is obvious, so we will make the criteria falsifiable.
An agency writing a guide to choosing agencies has an obvious conflict of interest, so let us defuse it the only honest way: every criterion in this piece is falsifiable. You can test each one against us and against everyone else on your shortlist, and the tests do not care who wrote them. That is rather the point — the agencies that fail these tests are counting on you not having a list.
Start with the question agencies hope you skip
"How will we know if this is working?" — asked before any contract, answered in writing. A serious agency answers with a measurement plan: which metrics govern (and which flattering ones explicitly do not), how brand and non-brand are separated, how incrementality gets sanity-checked, and what the honest evaluation window is. A weak agency answers with a ROAS number from another client's account. The difference between those two answers predicts the next two years of the relationship better than any case study.
The falsifiable questions
- "Walk me through a client you lost or fired, and why." Everyone has them. The answer tests honesty under mild social pressure — which is the same skill as honest reporting under bad-quarter pressure.
- "Who exactly will work on my account, and how many accounts do they carry?" Pitch teams and delivery teams diverge at most agencies. Ask for the operator, not the org chart.
- "Show me a report you send clients when performance is bad." The single most revealing artifact an agency possesses. If every sample report is a victory lap, you are looking at a marketing department, not a reporting function.
- "What happens to my accounts and data if we part ways?" The only acceptable answer: you own the ad accounts, the pixels, the audiences, and the historical data, and offboarding is documented. Anything else is a hostage situation with a monthly retainer.
- "What would you not do for us?" Operators with a methodology have refusals — channels they think are wrong for you, spend levels they will not endorse. Agencies without refusals are selling capacity, not judgment.
Read the incentive structure
Pricing models are not just commercial terms; they are behavioral predictions. Percentage-of-spend quietly rewards budget growth whether or not results follow. Pure performance deals sound aligned but push agencies toward harvesting easy wins (brand traffic, existing demand) and away from patient work that compounds. Flat retainers are the least glamorous and most neutral. There is no perfect model — what matters is whether the agency can articulate, unprompted, how their model could bias them and what governs against it. An agency that has never thought about its own incentives will follow them blindly.
A quiet structural signal: ask what the agency has built. Proprietary measurement infrastructure, audit tooling, documented methodology — investments in delivery capability rather than sales capability tell you where the operating margin gets reinvested. Deck quality tells you where it does not.
Red flags visible before signing
- Guaranteed results in a discovery call — nobody who has run real accounts guarantees outcomes before seeing your data.
- Audit findings that are all crisis and no nuance, delivered with a countdown-timer discount. Manufactured urgency is a pricing strategy, not a diagnosis.
- Reluctance to give you admin access to your own accounts "for technical reasons." There are no such technical reasons.
- Case studies with percentages and no context — "+400%" of an undisclosed base, in an undisclosed timeframe, is decoration.
- A pitch that never asks about your margins, sales cycle, or capacity. Anyone proposing spend levels without unit-economics questions is planning to optimize a number that is not connected to your business.
Weight the trial period over the pitch
The pitch measures sales skill; the first ninety days measure the actual product. Structure the start accordingly: a defined initial scope with explicit deliverables, a foundation-first plan rather than immediate spend heroics, and a pre-agreed review where either side can exit cleanly. Agencies confident in their delivery accept this readily. Agencies that resist a structured trial are telling you which part of their funnel is strongest — and it is not the part you are buying. If you want to see how we answer these questions ourselves, that conversation is free.
How much does a performance marketing agency cost?
Common models are a percentage of ad spend (typically 10 to 20 percent), a flat monthly retainer, or a hybrid with a performance component. For accounts spending $20k to $100k a month, expect roughly $2,000 to $10,000 monthly. The model matters less than the incentive alignment — pure percent-of-spend rewards spending more, not performing better.
What questions should I ask before hiring an ad agency?
Ask who will actually work on your account day to day, how they measure incrementality rather than platform-reported ROAS, what their first 90 days look like, why their last two clients left, and what happens to your account data and history if you part ways. The answers reveal more than any case study.
What are red flags when choosing a marketing agency?
Guaranteed results, reluctance to give you full ownership and admin access to your own ad accounts, reporting that leans on vanity metrics instead of revenue or pipeline, long lock-in contracts with no performance exit, and a pitch team you never see again after signing. Any one of these is a reason to keep looking.
How long should I give a new agency to show results?
Structural improvements — tracking, account structure, feed quality — should be visible inside 30 days. Meaningful performance movement typically takes 60 to 90 days, longer if your sales cycle is slow. What you should never accept is 90 days without a clear narrative of what was changed and why.
Written by The ADSRUNNER team. If this resonated and you want to apply it to your own account, you can book a strategy call or run a free audit.