GLOSSARY

The advertising cost for one thousand recorded ad impressions.

CPM helps media teams compare the price of audience exposure, plan reach-oriented budgets and monitor auction or inventory costs independently of clicks and conversions.

A campaign spends £4,800 and records 1,200,000 impressions. Its CPM is (£4,800 ÷ 1,200,000) × 1,000 = £4.

CPM measures delivery cost, not attention, unique reach, viewability, engagement or business outcomes. Invalid traffic, repeated exposure and inconsistent impression standards can distort comparisons.

CPM is calculated as advertising cost divided by measured impressions, multiplied by 1,000. It is both a buying model and a normalised delivery metric; the underlying impression definition and counting method must be consistent when comparing publishers, formats or campaigns.