# CPA

> Cost per acquisition: ad spend divided by the number of conversions.

Source: https://datacenter.so/glossary/cpa
Also called: cost per acquisition, cost per action, cost per result.

CPA = spend ÷ conversions. Name the conversion: cost per lead, cost per booked call, cost per purchase. A CPA is only useful when everyone knows which one it is.

Compare CPA with what a conversion is worth. For leads, that is the lead-to-sale rate times the average sale. For purchases, it is margin per order, and over time the customer's [lifetime value](https://datacenter.so/glossary/ltv).

## Related terms

- https://datacenter.so/glossary/roas
- https://datacenter.so/glossary/ltv
- https://datacenter.so/glossary/conversion