Flat Fee vs Percentage of Ad Spend: Paid Media Pricing

A flat fee is usually the fairer way to pay for paid media management, because it pays for the work and judgement rather than the size of your budget. Percentage of ad spend pricing ties the provider’s income to how much you spend, which quietly rewards spending more instead of spending well.

I charge a flat fee and have never charged a percentage of spend. Here is why, how flat fees work in practice, and what to ask any provider before you sign.

How does percentage of ad spend pricing work?

The agency charges a percentage of your monthly media spend as its management fee. Often there is a minimum fee, and sometimes the percentage tiers down as spend goes up. If you spend more on ads, they earn more. If you cut spend, their fee falls.

It is popular for understandable reasons. It is simple to quote, it scales automatically for the agency, and it feels proportional: a bigger budget sounds like more work.

Why does percentage of spend misalign incentives?

The problem is not that agencies on this model are dishonest. Most are not. The problem is that the model puts a thumb on the scale in several places.

The fee rises when spend rises, not when results improve

If a campaign is wasting money, the right move is often to cut spend. Under a percentage model, that recommendation directly reduces the provider’s income. Good people make that call anyway, but you are relying on them to act against their own commercial interest every month.

More budget does not mean more work

Managing £50,000 a month on a well-structured account is not five times the work of managing £10,000. Much of the effort, such as structure, tracking, creative testing and reporting, is similar at both levels. Percentage pricing charges you as if it scales in a straight line.

It encourages platform-friendly reporting

When income is linked to spend, there is a pull towards reporting that justifies spend, such as platform-reported ROAS and conversions. Platforms all claim credit for the same sale, so those numbers flatter almost everyone. I report against CRM pipeline in HubSpot or Salesforce and revenue in Shopify instead, which is how I tie spend to results on my B2B paid media work.

It penalises efficiency

If someone finds a way to hit the same pipeline for less spend, you should be pleased. Under a percentage model, they have just cut their own pay.

How does flat fee pricing work?

A flat fee is a fixed monthly amount for an agreed scope: which channels, how many markets, what reporting, and roughly how much time. The fee does not move when spend goes up or down within that scope.

That means:

• the provider’s recommendation to cut or increase spend is about results, not income
• you can budget for management cost in advance
• conversations about scope are explicit, because adding a channel or a market is a scope change, not an automatic fee increase hidden in the percentage

A flat fee is not a blank cheque for unlimited work. A good flat fee arrangement says what is included, and it gets reviewed when the job genuinely changes.

What do I charge?

My pricing is flat fee, never a percentage of spend:

• from £3,500 per month for one channel at an early-stage company
• most engagements between £6,000 and £10,000 per month, depending on channels, markets and reporting needs
• 30-day rolling contracts, so you can stop if it is not working

I work solo, so the fee pays for me doing the work across Google Ads, Meta, LinkedIn, TikTok and Microsoft Ads, not for a team you never meet. The full detail is on my how I work page.

Are there cases where percentage of spend makes sense?

Honestly, a few:

• very large, fast-changing media plans where spend genuinely drives workload, such as many markets launching and pausing every month
• short campaigns where scope is hard to define up front
• arrangements where the percentage is small, capped and paired with clear performance reporting

Even then, I would want a cap, a clear scope, and reporting against your own CRM or revenue data. A percentage with no ceiling and platform-only reporting is the combination to avoid.

What should you ask any provider about pricing?

Whether you are talking to an agency, a freelancer or a fractional lead like me, these questions get you a clear picture.

What exactly does the fee cover?

Ask for channels, markets, number of campaigns, creative production, landing pages and reporting. Find out what costs extra.

What triggers a fee increase?

Is it spend thresholds, new channels, new markets or extra hours? If spend alone moves the fee, you are on a percentage model by another name.

Who does the work?

Ask who logs into your ad accounts each week and how much of the senior person’s time you actually get.

What is the contract length and notice period?

Long minimum terms protect the provider, not you. Rolling monthly contracts keep everyone honest.

Who owns the accounts and data?

Your business should own the ad accounts, pixels, analytics and tag manager. The provider should be added as a user. If you leave, your history leaves with you.

What will results be reported against?

Ask whether reporting uses platform numbers or your CRM and revenue data. For B2B, that means pipeline and opportunities. For ecommerce, that means real orders and revenue. The FAQ covers how I approach this.

Are there any media markups or rebates?

Some providers mark up media or receive platform incentives. Ask directly, and ask for it in writing.

The short version

Pay for the work and the judgement, not the size of the budget. A flat fee, a clear scope, a short notice period and reporting tied to your real numbers is the setup that keeps a provider’s incentives pointed the same way as yours.

If you want a second opinion on how your current account is set up and what you are paying for, I offer a free account audit. I will look at structure, tracking and spend, and tell you plainly what I would change.

Questions people ask

What is percentage of ad spend pricing?

It is a fee model where the agency charges a percentage of the money you spend on ads each month, so the fee rises and falls with your media budget rather than with the work done.

Is a flat fee better than a percentage of spend?

For most companies, yes, because a flat fee removes the incentive to increase spend for its own sake. The fee should still be reviewed when scope genuinely changes, such as adding channels or markets.

How much does a fractional Head of Paid Media cost?

My own fees start from £3,500 per month for one channel at an early-stage company, and most engagements sit between £6,000 and £10,000 per month, as a flat fee on a 30-day rolling contract.

What should I ask an agency about pricing?

Ask what the fee covers, who does the work, what triggers a fee increase, what costs extra, what the notice period is, and who owns the ad accounts and data.