CPA (cost per action) is the cost of a single desired action: a purchase, a form submission, a sign-up or a phone call. You calculate it by dividing the campaign budget by the number of actions. If a £290 budget brought in 30 enquiries, your CPA is £9.67. You’ll also come across CPL (cost per lead), the cost of acquiring a new contact.
Why is CPA so useful?
Because it tells you directly what you pay for each result. A service business lives on enquiries, and clicks are only a step on the way to them. When we run Google Ads campaigns for local businesses, the conversation with the client starts with one question: how much can you pay for a single enquiry and still make the numbers work? If 10 enquiries turn into 3 jobs with £390 of margin each, even a £30 CPA is a great deal.
How do you lower CPA?
Three levers make the biggest difference: tighter audience targeting, a stronger offer on the landing page and trying out different creative (A/B testing). The most common mistake is cutting the budget. Spending less rarely brings CPA down. Better targeting and a page that keeps hold of people after the click usually do. Before you start optimising your ads, make sure you’re tracking conversions correctly in the first place.
Related terms: conversion, ROAS, lead.
