CPM or retainer? Programmatic advertising pricing models compared

What to take away

The four models English buyers actually see

Most programmatic contracts in England settle into one of four shapes. CPM charges per thousand impressions, so cost tracks delivery. CPA charges per acquisition, shifting risk to the seller. Retainers charge a fixed monthly fee for managed service. Percentage-of-spend takes a commission on media bought.

CPM pricing suits reach and awareness

CPM is the default for display, video and connected television. You agree a rate per thousand impressions and the platform optimises toward delivery. A campaign buying 4 million impressions at a £2.50 CPM costs £10,000 in media, before fees. That £2.50 is an illustrative example, not a market rate.

Cheap impressions are easy to buy and hard to value, so ask what viewability and brand-safety thresholds sit behind the rate. For the wider cost picture, including tech and agency fees, work through our programmatic advertising costs and budget guide.

CPA and hybrid pricing shift the risk

CPA pays only when a defined action happens, such as a completed enquiry. Sellers accept that when they control the funnel end to end. Otherwise they build a hybrid: a lower CPM plus a bonus per acquisition.

Hybrid deals need a precise definition of the conversion event and a dispute process. Without both, reconciliation drags. Performance models also narrow inventory, because the seller avoids placements unlikely to convert.

Retainers buy capacity, not outcomes

A retainer covers people and process: planning, trading, reporting and optimisation. A team paying £3,500 a month for managed service is buying roughly a day a week of specialist time, as an illustrative example. Media spend sits on top.

Retainers work when the work is continuous and the scope stable. They fail when scope creeps without a change process, so link fees to named deliverables and review scope quarterly.

Percentage-of-spend pricing and its incentives

Commission models charge a percentage of media bought, often between 10% and 20% in agency contracts. That rewards growing spend rather than improving efficiency, so pair commission with a maximum cost per acquisition.

Ask whether commission applies to gross or net media cost, and whether tech fees sit in the base. Small wording differences change the invoice.

Where AI changes the pricing conversation

Automated bidding and creative optimisation sit inside most platforms, which pushes pricing toward outcomes. The IAB's work on artificial intelligence in advertising covers how these applications are being adopted across programmatic buying.

Sellers using automation often argue for performance fees, since their systems influence the result. Test that claim against a control group before agreeing a higher variable rate.

Comparing a platform PPC rate

When programmatic is weighed against search or social, a simple per-click format helps. LinkedIn's text ads format is a basic pay-per-click option, useful as a benchmark when a client asks why display is priced per impression.

A quick glossary

Common questions

Which model is cheapest?

None is cheapest in every case. CPM looks cheap per unit but can waste budget on poor placements, while CPA looks expensive per unit but charges only on results. Compare total cost against a defined outcome.

Can I mix models in one contract?

Yes, and hybrid deals are common. Keep the base fee, the performance trigger and the reconciliation window in one written schedule so invoices can be checked.

How often should pricing be reviewed?

At least every six months, or sooner if inventory costs move. Our programmatic advertising cost guide for England sets out the review points to diarise.

Do performance deals remove the need for compliance checks?

No. Lawful targeting and consent still apply whoever carries the pricing risk, so keep the data basis documented whatever the model.