Foundations
Part of What should buyers know about marketing agency foundations?
Marketing agencies business models shape what a client actually buys
Compare marketing agencies business models in England: retainer, project and performance fees, plus how the ONS measures the industry and who buys agency work.
What to take away
- Decide what you are buying: a retainer buys capacity, a project buys a defined output, a performance deal buys a result.
- Most agencies run hybrids, so check which element dominates the contract rather than the label on the proposal.
- Retainers reward time spent, while performance fees shift risk to the agency and usually carry a higher headline rate.
- Official output data for advertising and market research is published quarterly by the ONS on a UK basis, not an England-only basis.
Retainer agencies sell capacity, not campaigns
A retainer is a monthly fee for an agreed number of days or a named team. The client buys access rather than a finished item, which suits ongoing search and content work.
The risk sits with the buyer. If the scope is loose, hours drift towards whatever the agency finds easiest. A monthly breakdown of days by discipline is the main protection.
Retainers give the agency recurring revenue, which is why they carry a premium.
Project agencies sell a defined output
A project fee covers one deliverable: a website build, a brand refresh, a paid media launch. The price is fixed before work starts, so the agency carries the risk of overrunning.
This suits a business that knows what it wants and has someone internal to sign it off. It also favours agencies that estimate scope accurately.
Watch the change-control clause. Most project disputes come from work the client assumed was included.
Performance and commission models sell an outcome
Performance fees tie payment to a metric: leads, sales, or a share of ad spend. Commission on media spend remains common in paid media.
The Google Ads overview of how campaigns are billed shows why spend-based commission is easy to administer but weakly linked to profit. An agency paid a percentage of spend has little reason to reduce that spend.
Lead-based deals align interests better, provided the definition of a lead is written down and a rejection process is agreed before launch.
How the industry is measured in England
The Office for National Statistics publishes quarterly output figures for advertising and market research, the closest official read on sector fee income. Its ONS quarterly output series for advertising and market research is compiled on a UK basis, covering Scotland, Wales and Northern Ireland as well as England.
That matters when an agency quotes sector growth at you. Our marketing agencies England market guide for 2027 sets out how the buyer side is structured before you shortlist.
Who buys agency services
Advertiser membership bodies represent the demand side. The ISBA advertiser membership pages describe a body whose members commission agency work across brand, media and performance.
Where a large advertiser brings procurement in, the model tends towards retainer plus performance. Where the buyer is founder-led, project and hybrid fees dominate. That split between the main marketing agencies business models explains why two similar agencies can quote very differently for the same brief.
A worked example with labelled figures
Suppose a Manchester retailer wants search, paid social and content for a year. Three quotes arrive.
Three agency quotes compared
Agency A
- Model
- Retainer
- Fixed fees
- £72,000
- Commission
- None
- Total year one
- £72,000
- Scope risk
- Buyer
Agency B
- Model
- Project + retainer
- Fixed fees
- £60,000
- Commission
- None
- Total year one
- £60,000
- Scope risk
- Agency
Agency C
- Model
- Retainer + commission
- Fixed fees
- £30,000
- Commission
- £38,400
- Total year one
- £68,400
- Scope risk
- Shared
Agency A: a retainer of £6,000 a month for twelve days of work, with no performance element. Total £72,000 for the year.
Agency B: a project fee of £18,000 for a site rebuild, then £3,500 a month. Total £60,000, with the rebuild fixed in scope.
Agency C: £2,500 a month plus 8 per cent of ad spend, with spend forecast at £40,000 a month. That is £30,000 in fees plus £38,400 in commission, so £68,400.
All figures are illustrative. Agency C looks cheapest on the retainer line and dearest once commission is counted. Our marketing agencies commercial opportunities article covers where negotiation is possible.
Common questions
Is a retainer always more expensive than a project fee?
No. A retainer usually costs more in total because it buys continuous capacity, but the effective day rate is often lower. Compare the day rate, not the headline total.
Which model suits a business with no marketing team?
A retainer with a named team, because someone has to direct the work. A project fee assumes the client can write the brief.
Do performance fees work for small advertisers?
They can, but only with a written definition of the qualifying action and a rejection process. Without both, agency and client disagree about what counts.
Are these models different in Scotland or Wales?
Fee structures are the same across Great Britain. What differs is the supply of agencies and the sectors they serve, so a buyer outside England may face a shorter shortlist.
