Performance marketing agency: the fee model decides how the agency behaves, so price it before you compare pitches

A performance marketing agency buys and manages advertising judged on a measurable action: a sale, a lead, an install, a booking. Paid search, paid social, shopping, display, retargeting, affiliate and increasingly retail media all sit under the label. You are hiring account operators, a measurement setup and somebody accountable for a cost per acquisition, which is neither brand advertising nor advice. The most consequential decision is not which agency to appoint. It is how they are paid, because the fee model shapes every recommendation they make for the next two years.

Three jobs sold under one phrase

• Channel operations. Running the accounts well: structure, bids, budgets, negatives, audiences, feeds, creative rotation. The commonest version and the easiest to judge.
• Full funnel acquisition. Media plus landing pages, creative production and the measurement connecting a click to revenue. Dearer, and the only version you can hold to a blended cost per customer.
• Partner and affiliate performance. Publishers, influencers and comparison sites paid on outcome. Its own discipline with its own networks and contracts, often bolted onto a search retainer and then neglected.

Ask which of the three the proposal is scoped for, and ask who produces creative. In paid social the creative is the targeting now, so an agency with no production capability and no budget line for it plateaus within a quarter whatever it does to the bidding. Buying senior advice instead of execution is a different engagement, covered in the guide to hiring a performance marketing consultant.

US fee ranges, by how much you spend

The ranges here are my own read of the US market rather than a published benchmark, gathered from scopes and fee conversations, and they move with channel count and creative load. They are useful mainly for recognising a quote that sits well outside the norm.

Monthly media spend	Typical percentage of spend fee	Typical flat retainer instead	What the fee should include at that level
Under 10,000 dollars	Rarely workable; expect a minimum fee	2,500 to 4,500 dollars	One or two channels, monthly reporting, no creative
10,000 to 50,000 dollars	15 to 20 per cent	4,000 to 9,000 dollars	Two or three channels, tracking maintained, fortnightly calls
50,000 to 250,000 dollars	10 to 15 per cent	9,000 to 20,000 dollars	A named team, a test roadmap, feed management, weekly reporting
250,000 to 500,000 dollars	7 to 10 per cent	20,000 to 35,000 dollars	Dedicated analyst, incrementality testing, a quarterly plan your finance team reads
Above 500,000 dollars	5 to 8 per cent	Negotiated, often on headcount	Priced on the team assigned, against an agreed efficiency target

Four more lines show up around those. A minimum monthly fee, usually 2,500 to 6,000 dollars, applied whatever the percentage produces. A one off measurement and tracking rebuild at 6,000 to 25,000 dollars, money well spent before any media scales. Creative production as an add on, 2,000 to 10,000 dollars a month. And a hybrid of a 3,000 to 8,000 dollar base plus 5 to 10 per cent of spend, which most mid market agencies prefer. A freelance media buyer runs 85 to 200 dollars an hour, or 1,000 to 2,000 a day.

Do the arithmetic on the fee before you compare pitches

Percentage of spend is the dominant model here and it has one structural property worth pricing out loud: the agency earns more when you spend more, whether or not the extra spend works. Manageable, but only once you have looked at the numbers.

Take a 40,000 dollar monthly budget at a 15 per cent fee. That is 6,000 dollars to the agency and 46,000 leaving your bank. If the programme returns 184,000 dollars, your true cost of media is 25 per cent of revenue rather than the 21.7 per cent the platform dashboard implies, because the dashboard knows nothing about the fee. Now the agency proposes doubling the budget to 80,000 dollars. Their fee goes to 12,000 automatically, with no new commitment. Unless efficiency holds at double the volume, which in paid search it often does not, your cost of media as a share of revenue rises and the agency's income rises with it.

Two terms fix this without changing the model. Agree a target efficiency expressed as revenue per dollar of total cost including the fee, and write in that the percentage steps down at named spend thresholds. A confident agency accepts both, because a declining rate at higher volume reflects what happens to the workload.

The same check applies to outcome based fees. A cost per lead arrangement sounds safer and shifts the risk onto lead quality: the agency is paid for volume and your sales team absorbs whatever arrives. Define a qualified lead with sales, pay on the qualified count from your own system, and put the definition in the contract before the first invoice.

Accounts, data and access, settled first

• Every ad account created and billed in your company name, agency granted admin rights. Business manager level, merchant centre and retail media accounts included. Agency owned ad accounts are the dearest handover problem in this industry.
• Tag management and analytics in your container, your property, your data. Not a copy, and not an agency workspace you have read access to. Account history is what makes the next agency effective in week two rather than month three.
• A named team, with its time allocation and a substitution clause.
• Thirty days notice with an attached handover list: documentation, the test log, the roadmap, naming conventions, reporting definitions.
• Claim substantiation. Copy making a performance, pricing or comparison claim needs evidence behind it, and under US advertising rules the advertiser carries that duty whoever wrote the ad. Agree who holds the file for every claim running in your account.

Five questions worth more than a credentials deck

• Walk me through an account you inherited and what you turned off in the first month. People who have run real budgets have a view on waste before they have one on growth.
• What would you want to see from us in week one? A strong answer asks for margin by product and revenue from your own system, not platform screenshots.
• How will you tell whether this spend is incremental? Holdouts, geographic splits, paused brand campaigns, a lift test. A team that treats platform reported conversions as the answer will overstate its own effect all year.
• How does your fee change if we double the budget, and if we halve it? Ask directly and watch how comfortable they are.
• Which channel would you refuse to add for a business like ours? An agency that will sell you every channel is one that sells channels.

When an agency is not the right line item

• Spend below roughly 10,000 dollars a month. A minimum fee eats a crippling share of it, and a freelancer delivers more per dollar.
• Your tracking is broken. Buy the measurement project on its own first. Media managed against numbers nobody trusts produces a monthly argument rather than a decision.
• Spend above a few hundred thousand a month in one or two channels. An in house buyer plus a consultant on a day rate for governance costs less than a percentage fee and keeps the knowledge in the building.
• The offer is the problem. Where the product, price or landing experience is losing to competitors, no amount of bid management closes the gap, and a good agency says so on the first call.

What paid media buyers ask before they sign

Is percentage of spend or a flat retainer better?

A flat retainer is cleaner, because the fee does not move with a decision the agency recommends. Percentage of spend scales more easily and is what most agencies offer. Add stepped rates at spend thresholds and a stated efficiency target and the two behave much the same.

How long before a new agency improves the numbers?

Measurement and waste fixes land in the first four weeks. Changes to campaign architecture and bidding need a full learning cycle, commonly four to six weeks before the data reads clearly. Creative testing moves at whatever pace your approvals allow, usually the real constraint. Ninety days is the fair first review.

Who should the ad accounts belong to?

You. Create them yourself, bill them to your own card or credit line, and grant the agency admin access. Getting this wrong costs years of account history and audience data on the day you change supplier.

Which lines belong in the channel report?

Spend and fee separately, cost per acquisition from your own system rather than the platform, new customer share, contribution after media by channel, the tests concluded, and what is being stopped. A report built on platform conversions alone describes the dashboard rather than the business.

The acquisition channel that has no bid and no invoice

Performance marketing is organised around surfaces you can buy: an auction, a placement, a partner. Upstream of all of them sits a surface with no auction attached. A buyer asks ChatGPT, Gemini, Perplexity, Claude or Google AI Overviews which option to pick in your category, reads a composed answer naming two or three companies, and either arrives already persuaded or never arrives. The ad platform does not record it, and it bends the numbers that are recorded, because a prospect who saw your name in that shortlist converts differently from one who met you cold in a feed. No bid places you there. The input is text about your business a model can reach and trust. AI Knows Us turns it into a monthly line on the report: the question, the answer, the companies in it, the citations under it. aiknowsus.com.