The core metrics
- New customers or orders.
- Customer acquisition cost: total marketing spend ÷ new customers.
- Conversion rate: from enquiry to sale.
- Average order value.
- Customer lifetime value: how much they buy over, say, a year.
A one-page monthly report
A simple table: spend, new customers, cost per customer, revenue, comparison with last month, and three notes: what worked, what stopped, and the next test.
Read the context
A higher cost per customer isn’t always bad if the new customers are worth more. Read the metrics together, not each number alone.