When to rebuild a programmatic advertising cost guide

What to take away

Why the model goes stale

A cost guide fails quietly. Nothing breaks on the day a supply-path fee changes or a floor resets. The model simply returns a number that no longer matches what finance pays.

Most English agencies rebuild in the wrong order. They start with the headline cost per thousand and work backwards, which forces every other line to absorb the error. Start with the invoice instead.

Sort fixed from variable

The distinction matters because a fixed line can be renegotiated mid-term. A variable line cannot be argued with, only planned around. For a fuller breakdown of which lines sit in each camp, the costs and budget guide for England sets out the categories in order.

Where the numbers come from

Use three sources, ranked. Your own invoices come first. Platform documentation comes second. Published benchmarks come third, and only to test whether your figures are plausible.

Google's own help documentation on how cost per click is set in Google Ads explains that the amount you pay is determined by the auction, not by a fixed rate card. That is the mechanic behind most variable lines in a programmatic plan.

LinkedIn publishes advertising cost and pricing benchmarks for its own inventory, which is useful when a client asks whether a quoted figure is normal. It is not a proxy for open-exchange pricing.

The before and after table

Build one table per client, not one for the agency. The figures below are illustrative for a team spending £40,000 a month on media.

The point of the table is not the total. It is that one line moved and five did not. A rebuild that shifts every line at once usually means the analyst changed method, not the market.

Choosing a pricing model

The rebuild will keep failing if the pricing model underneath it is wrong. A percentage-of-media model rewards spend. A fixed-fee model rewards scope control. A performance model moves risk to the agency.

Each behaves differently when media budgets fall. If the commercial shape needs revisiting before the cost lines do, programmatic advertising pricing models in England compares how each one pays out across a year.

Creative and format costs

Format choice changes cost per unit of attention, not just cost per impression. Native and sponsored placements carry production overhead that display does not.

IAB UK's native distribution principles for creative best practice set expectations for how native creative should be labelled and built, which feeds directly into the production hours you must budget.

Common questions

How often should a cost guide be rebuilt?

Twice a year is usually enough, plus an out-of-cycle rebuild whenever a contract renews or a platform changes its fee structure. Rebuilding more often than that tends to produce noise rather than accuracy.

Should the guide use blended or line-by-line figures?

Line by line. Blended figures are fine for a client summary, but they hide the movement you need to see when an input changes. Keep the detail in the working model and blend only at the point of presentation.

What counts as a material change worth a rebuild?

Any single line moving by more than 5% of the total monthly cost. Below that, note it and carry on. Above it, re-run the table and check whether the change is permanent or a one-off.

Can a published benchmark replace invoice data?

No. Benchmarks are aggregated and lag the market. Use them to challenge your own numbers, never to set them, because your auction results and fee terms are specific to your account.