Cost Per Action (CPA) / effective Cost Per Action (eCPA)

A pricing model in online advertising marketing strategies in which an advertiser pays per conversion (e.g. file download or form registration).

CPA = total cost of campaign ÷ number of conversions

This model also covers other options depending on the ad’s goal and involves cost per download (CPD) and cost per install (CPI).

One of the key benefits of CPA is that advertisers only pay when a specific action takes place.

eCPA means effective cost per acquisition. It tells us what the CPA would have been if the advertiser had purchased conversions instead of impressions or clicks.