CPT, or Cost Per Thousand Contacts, shows what it costs to deliver one thousand contacts with a message and is an established metric across multiple media channels, not only in OOH. In out‑of‑home advertising, CPT is used to understand how cost‑efficiently a campaign delivers reach, based on the contacts the sites actually generate.

In OOH and DOOH, CPT is typically calculated by dividing the campaign’s net cost by the total number of contacts, often based on VAC, and then multiplying by one thousand. This makes the metric useful when comparing different sites, formats and packages, but also when positioning out‑of‑home against other channels using the same cost language.

For advertisers, CPT therefore becomes a simple and practical way to assess whether the investment is delivering sufficient reach and contact value for the money. The stronger the contact delivery to the right target audience, the more attractive the CPT becomes within the overall media mix.