Unit Economics
Moving from 'Total Cost' to 'Cost Per X'.
Just because your cloud bill went up doesn't mean you are doing a bad job. If your user base doubled, your bill should go up. Unit economics measures efficiency relative to business value.
The Golden Metric
Cost per Transaction / Customer / Order
Healthy Growth
Total Spend is UP, but Cost Per Customer is FLAT or DOWN. This means you are scaling efficiently.
Unhealthy Growth
Total Spend is UP, and Cost Per Customer is UP. Economies of scale are working against you.