---
title: "PPC management fees: why percentage of spend is the wrong model"
url: https://marketingsignals.com/insights/ppc-management-fees-percentage-of-ad-spend
type: Article
date: 2026-11-01
author: "Laura Salini"
---

# PPC management fees: why percentage of spend is the wrong model

Why PPC management fees charged as a percentage of ad spend reward the wrong things, and how a fixed fee scoped on account complexity works better.

## Key takeaways

- A percentage-of-spend fee pays the agency more when you spend more and less when it cuts waste, so the model works against efficiency.
- A fixed fee is one predictable number that finance can plan for, approve once and put on a single purchase order.
- PPC work scales with account complexity (campaigns, markets, languages, feeds, tracking, platforms), not with spend, so doubling budget rarely doubles the work.
- With Smart Bidding and Performance Max allocating much of the spend, the agency's value sits in strategy, conversion data, feeds, testing and controls.
- Scope a fixed fee on complexity, judge it on agreed business KPIs, review it at set points, and keep ad accounts and media billing in your own name.

Most conversations about PPC management fees start with the rate. The more useful question is what the fee is tied to. Many agencies charge a percentage of monthly ad spend, and we think that is the wrong model for any brand spending enough to need an agency.

Our objection is not that the fee is too high or too low. It is that the structure pays the agency for the size of your budget rather than the quality of its work. Every pound of waste the agency cuts lowers its own fee, and every budget increase it recommends raises it. It also makes the fee harder for your finance team to plan, approve and raise a purchase order against.

This article sets out why, where a percentage fee can still seem reasonable, and what a better arrangement looks like. It should help you judge your current agreement and decide what to ask for at the next renewal.

## The incentive runs the wrong way

A percentage fee means the agency earns more when you spend more, whatever that spend achieves. That is a conflict of interest written into the commercial agreement, and it touches the most important advice an agency gives you: how much to spend.

When an agency on a percentage fee recommends a bigger budget, it may well be right. You just cannot tell whether the advice comes from the data or from the invoice. Google Ads already [recommends higher budgets](https://support.google.com/google-ads/answer/2375420?hl=en-GB) for campaigns that keep reaching their daily limit. The agency should be the one checking whether the extra spend would pay back at the margin, and a percentage fee pays it to agree.

As an illustration, using round, hypothetical numbers: on an account spending £50,000 a month, cutting £5,000 of waste lowers a percentage fee by a tenth. Persuading the client to spend £70,000 raises it by two fifths. Neither change needs to alter the hours the team puts in.

## A fixed fee is easier to budget and approve

The second problem lands with finance. A percentage fee is a variable cost that nobody can state in advance. Marketing has to forecast spend, then forecast the fee from the spend, then explain both whenever either one moves.

A fixed fee is one number per month or per quarter. It can go into the annual plan, be approved once and sit on a single purchase order. In our experience, procurement teams in mid-market and enterprise businesses approve a fixed amount far more readily than an open-ended percentage, and it stops the agency fee being reopened every time the media plan changes.

Seasonality widens the gap. For a retailer whose spend peaks around Black Friday and Christmas, a percentage fee peaks in the same months, exactly when budgets are most stretched. The fee then swings from month to month, which is the kind of variance finance teams ask marketing to explain.

## The work that saves money cuts the agency's fee

Much of the most valuable PPC work reduces spend, or moves it from activity that looks good to activity that pays. Under a percentage model, each of these lowers the agency's income:

- Adding [negative keywords](https://marketingsignals.com/glossary/negative-keywords) from weekly search term reviews, so budget stops going on searches that never convert.
- Pausing or cutting campaigns that miss their target CPA or ROAS, rather than keeping them alive for volume.
- Applying [brand exclusions](https://support.google.com/google-ads/answer/14505308?hl=en) to Performance Max, so it stops claiming brand searches you would have won anyway.
- Fixing conversion tracking, which often shows that some spend was buying conversions that were never real.
- Testing whether brand ads are incremental, and reducing brand spend where they are not.

## Brand bidding shows the problem most clearly

Brand clicks are usually the cheapest in the account and the easiest to report on, so brand campaigns make a percentage-fee account look efficient. A proper [incrementality test](https://marketingsignals.com/glossary/incrementality-testing), holding brand ads off in some regions or periods and comparing total sales, can show that part of that spend buys sales your organic listing would have won. Our note on [paid and organic overlap](https://marketingsignals.com/glossary/paid-and-organic-overlap) covers why that happens.

Acting on that result is good for you and bad for a percentage fee. We are not saying agencies on percentage fees avoid this work. Many do it well. The point is that the model penalises them for it, and you should not have to rely on an agency acting against its own commercial interest.

We set out how we run that test, and how we report it, in [our brand bidding incrementality article](https://marketingsignals.com/insights/brand-bidding-incrementality-test).

## The fee does not follow the effort

The work in a PPC account scales with complexity, not spend. What takes time is the number of campaigns, markets and languages, the size and quality of product feeds, the state of conversion tracking and CRM imports, the number of platforms, and the reporting the business needs.

Doubling the budget on a stable account rarely doubles any of that. The same campaigns run with higher budgets and adjusted targets. A percentage fee doubles anyway.

The reverse also happens. A modest budget spread across six markets, three languages and a large product feed is far more work than a large budget in one market, yet a percentage model pays less for it. Over time this becomes a scale penalty: as the account grows, the fee grows in line with it for broadly the same team, and the reward for success is a larger agency bill.

## Automation moved the work away from spend

Manual bid management used to be a real part of the job, and it did grow with spend. That is no longer how most accounts run. Google describes [Smart Bidding](https://marketingsignals.com/glossary/smart-bidding) as bidding strategies that [use Google AI to optimise for conversions or conversion value in every auction](https://support.google.com/google-ads/answer/7065882?hl=en-GB), and it needs conversion tracking switched on to work.

[Performance Max](https://marketingsignals.com/glossary/performance-max) goes further. Google says it gives access to all Google Ads inventory from one campaign and [automatically funnels your budget towards the highest-performing inventory and placements](https://support.google.com/google-ads/answer/10724817?hl=en-GB). The advertiser supplies the inputs: conversion goals and targets, assets, audience signals, data feeds and controls such as brand exclusions.

So the agency's value now sits in those inputs: the strategy, the quality of conversion data sent back to the platform, the feed, the testing programme and the controls that stop automation buying the wrong traffic. That is scoped work with a clear list of deliverables. It does not get bigger because Google is spending more of your money.

## Small campaigns with strong returns get ignored

A percentage fee also shapes where the agency spends its time. Activity with low spend and strong returns earns the agency very little, so it tends to sit at the bottom of the list.

Microsoft Ads is a common example: often a fraction of the Google budget, but worth running well for many brands. Brand protection against competitors bidding on your name, remarketing tests and small campaigns for high-margin product lines fall into the same group. Each takes time to set up and maintain, and under a percentage model that time is poorly paid. Under a fixed fee, it is simply part of the agreed scope.

## Where a percentage fee can seem fair

There are cases where a percentage fee is reasonable. On a very small or brand-new account, with no history to scope against, a percentage can be a simple starting point. Where an agency also funds media on the client's behalf and carries the credit risk, a margin on spend reflects a real cost.

Fixed fees carry their own risk. If the scope is vague, an agency can take a fixed fee and quietly do less, and the client may not notice until results slip. The answer is not to tie the fee to spend. It is to write down what the fee buys, report against it and review it at set points.

## What PPC management fees should pay for instead

The model we think works for mid-market and enterprise brands has five parts.

1. A fixed fee scoped on complexity. The fee is set from the work the account needs: campaigns, markets, languages, platforms, feeds, tracking and reporting. It is agreed in advance and does not move with spend.
2. Clear deliverables. The scope lists what happens each week, month and quarter, such as search term reviews, feed updates, tests run and reports delivered, so either side can check it is being done.
3. Business KPIs, not spend. Success is measured on agreed numbers such as [cost per acquisition](https://marketingsignals.com/glossary/cost-per-acquisition), [ROAS](https://marketingsignals.com/glossary/roas), profit or qualified pipeline, so budget advice is judged on whether it pays back.
4. Set review points. Scope and fee are reviewed quarterly, or sooner when the account changes shape with a new market, platform or product range. That protects both sides from drift.
5. An optional bonus tied to outcomes. If both sides want shared upside, a bonus can be linked to agreed profit or pipeline targets. It should never be linked to spend.

## Account ownership and media billing

Two things sit underneath all of this. The ad accounts stay in the client's name, with the client holding [admin access](https://support.google.com/google-ads/answer/9978556?hl=en-GB), which in Google Ads is the level that controls user access, manager account links and payment details.

Media spend is paid directly to the platforms on the client's own billing. There is no mark-up on media, the agency fee is visible as a separate line, and nothing needs unpicking if the relationship ends.

## Questions to ask your current agency

- If we cut our budget by a fifth, what would happen to your fee, and to the work you do?
- Which of your recommendations in the last six months reduced our spend, and what did they save?
- Have we tested whether our brand ads are incremental, and what did the test show?
- Who owns our ad accounts and billing, and is there any mark-up on media?
- What exactly does the fee buy each month, and where is that written down?

## Moving from a percentage fee to a fixed fee

Changing the fee model does not need to disrupt performance, because nothing in the account has to change on the day the contract does.

1. Agree the scope first. List the work the account needs today, using the last six to twelve months of activity, and price that rather than the spend.
2. Record the baseline. Note current CPA, ROAS or pipeline figures so the new arrangement is judged against a known starting point.
3. Check ownership. Confirm the accounts, conversion tracking and billing sit with you before signing anything new.
4. Switch at a quiet point. Avoid changing fee models in the run-up to a seasonal peak, when any change in focus costs most.
5. Review after the first quarter. Compare the work delivered and the results with the scope, and adjust the fee if the account has changed shape.

## How we scope a fixed PPC fee

When we price [PPC management](https://marketingsignals.com/service/pay-per-click), we look at account complexity, the markets and languages involved, the platforms, the product feeds, the state of tracking and CRM imports, and the reporting leadership needs. The fee is fixed for that scope, accounts stay in your name and spend goes straight to the platforms.

If you want a second view on your current agreement, or a fixed quote for your account, [get in touch](https://marketingsignals.com/contact-us).

We scope fixed fees the same way for [e-commerce](https://marketingsignals.com/service/pay-per-click/ecommerce-ppc), [B2B and lead generation](https://marketingsignals.com/service/pay-per-click/b2b-ppc) and [law firm](https://marketingsignals.com/service/pay-per-click/ppc-for-law-firms) accounts.

## Frequently asked questions

### How much do PPC management fees cost?

There is no single market rate. Agencies usually charge a percentage of monthly ad spend, a fixed monthly fee, or a mix of the two. A fixed fee should be scoped on account complexity: campaigns, markets, languages, platforms, product feeds, tracking and reporting. When comparing quotes, look at what the fee includes, who owns the ad accounts and how results are measured, not only the headline figure.

### Is a percentage of ad spend a fair way to pay a PPC agency?

For most established accounts, no. A percentage fee rises when spend rises and falls when waste is cut, so the agency is paid more for recommending bigger budgets and less for making the account more efficient. It can be a reasonable starting point for a very small or brand-new account, or where the agency funds media itself and carries the credit risk.

### What is the difference between a fixed fee and a percentage of spend for PPC management?

A percentage fee is a share of what you spend on media each month, so it changes whenever the budget does, including during seasonal peaks. A fixed fee is an agreed amount for a defined scope of work, set in advance. It is easier to budget for and to approve on one purchase order, and it removes the link between the agency's income and your spend.

### Should a PPC agency mark up media spend?

In most cases it should not need to. If the ad accounts are in the client's name and spend is paid directly to Google, Microsoft or other platforms on the client's own billing, there is nothing to mark up. The agency fee is then a separate, visible line, and the client keeps full control of the accounts if the relationship ends.

### How do you stop a fixed-fee PPC agency doing less work over time?

Write the scope down. List the deliverables for each week, month and quarter, such as search term reviews, feed updates, tests and reports, and agree the business KPIs the work is judged on, such as CPA, ROAS, profit or pipeline. Review scope, results and fee at set points, usually quarterly, and whenever the account adds markets, platforms or product ranges.

## Sources

- [Google Ads Help: About Smart Bidding](https://support.google.com/google-ads/answer/7065882?hl=en-GB)
- [Google Ads Help: About Performance Max campaigns](https://support.google.com/google-ads/answer/10724817?hl=en-GB)
- [Google Ads Help: Apply brand exclusions to Performance Max or Search campaigns](https://support.google.com/google-ads/answer/14505308?hl=en)
- [Google Ads Help: Set and change an average daily budget for your campaign](https://support.google.com/google-ads/answer/2375420?hl=en-GB)
- [Google Ads Help: About access levels in your Google Ads account](https://support.google.com/google-ads/answer/9978556?hl=en-GB)

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