Why unit economics matters more than revenue
Revenue can grow on top of a loss-making model. Unit economics asks the harder question: are we making money on each customer, on each order? Only with positive unit economics does scaling increase profit rather than losses.
There are two main levels of analysis:
- Customer level: LTV / CAC
- Order level: revenue − COGS − shipping − returns = margin per order
Calculating LTV/CAC in e-commerce
The base LTV formula for e-commerce:
LTV = AOV x Gross Margin % x Purchase Frequency (per year) x Avg. Customer Lifespan (years)
Example:
AOV = $45, Margin = 35%, Frequency = 3 per year, Lifespan = 2 years
LTV = 45 x 0.35 x 3 x 2 = $94.50
CAC = $28
LTV/CAC = 3.4 <- a healthy figure
The standard benchmark is LTV:CAC of 3 or more. Below 2 is a warning sign. Below 1 the business loses money on every customer it acquires.
How individual metrics move unit economics
| Metric | Effect on unit economics |
|---|---|
| AOV (+10%) | LTV rises proportionally |
| Repeat purchase rate (+15%) | Frequency rises, so LTV rises |
| Retention rate (+5%) | Lifespan rises, so LTV rises |
| CAC (−20%) | The LTV/CAC ratio improves |
| Gross margin (+3 pp) | LTV rises with no change in behaviour |
Personalization pulls several levers at once: recommendations raise AOV, triggered marketing raises frequency, better retention extends lifespan.
Important: unit economics is a snapshot built on historical data. When the acquisition cohort changes — different channels, a different value proposition — the LTV of future customers can differ sharply from the historical figure. Recalculate by acquisition cohort rather than across the whole base.