Unit Economics
Unit economics is the per-customer or per-order math that decides whether scaling spend grows profit or burns it. Here's the formula, the benchmarks, and how to read the result.
Unit Economics
The profit or loss a business makes on a single customer or order once variable costs and acquisition costs are subtracted.
Unit economics is the per-unit view of profitability — usually framed as one order or one customer relationship. You take the revenue that unit generates, subtract the variable costs to fulfil it (COGS, payment fees, shipping, returns) to get contribution margin, then subtract the acquisition cost to get a net contribution per customer.
The number tells you something the P&L can't: whether each incremental order makes the business stronger or weaker. If unit economics are positive and stable, scaling paid spend compounds profit. If they're negative, every new customer makes the loss bigger — and growth is the problem, not the solution.
Most online stores look healthy at the top of the funnel and break down at the unit level. Revenue grows 40% year-over-year, but contribution margin per order is quietly shrinking because shipping costs rose, return rates crept up, or paid CAC drifted from €18 to €34 while AOV stayed flat.
Unit economics is the diagnostic that surfaces this drift early. It sits inside the broader practice of revenue intelligence — the discipline of understanding which orders, channels, and cohorts actually fund the business — and it's the number you should be able to recite for your top three acquisition channels without opening a spreadsheet.
Contribution per Customer = (AOV × Orders per Customer) − Variable Costs − CAC
AOV
Average Order Value
Mean revenue per order, net of discounts and VAT.
Orders per Customer
Repeat factor
Average number of orders a customer places over the measurement window (often 12 months).
Variable Costs
Variable costs per customer
COGS, payment processing, shipping, packaging, and returns allocated across all orders that customer places.
CAC
Customer Acquisition Cost
Blended or paid-channel cost to acquire one new customer.
A Shopify apparel store looking at its Meta-acquired cohort.
AOV: €72
Orders per customer (12 mo): 1.6
Variable cost rate: 48% of revenue
Paid CAC: €38
→ Contribution per customer = (72 × 1.6) − (72 × 1.6 × 0.48) − 38 = €115.20 − €55.30 − €38 = €21.90
Each Meta-acquired customer nets €21.90 over 12 months. Positive, but thin — a 10% CAC increase wipes out a third of that margin, so the channel is one auction shift away from breaking even.
The number you want depends on the maturity of the business and the channel. Early-stage stores often tolerate near-zero or slightly negative first-order economics if cohort data shows reliable repeat behaviour. Established brands with weak repeat should expect positive contribution on the first order — there's no second order to bail them out.
Typical per-customer unit economics by vertical (12-month window, blended paid + organic)
| Vertical | AOV | Variable cost % | Orders / customer | CAC | Contribution / customer |
|---|---|---|---|---|---|
| Apparel & accessories | €65–€90 | 45–55% | 1.4–1.8 | €28–€42 | €15–€35 |
| Beauty & skincare | €38–€55 | 35–45% | 2.2–3.0 | €18–€32 | €25–€55 |
| Home & lifestyle | €85–€140 | 50–60% | 1.2–1.5 | €35–€55 | €10–€40 |
| Consumer electronics | €120–€220 | 65–78% | 1.1–1.3 | €40–€70 | €-5–€25 |
| Supplements & food | €42–€68 | 30–40% | 2.8–4.0 | €22–€38 | €45–€95 |
Read the table as ranges, not targets. A beauty brand with three orders per customer per year is playing a fundamentally different game than an electronics store with 1.2 — the levers (retention, replenishment cadence, subscription) differ, and so does the right CAC ceiling. Unit economics is always relative to the repeat profile your category actually delivers.
Frequently asked questions
Gross margin is revenue minus COGS at the company level. Unit economics is the per-customer or per-order view that also subtracts payment fees, shipping, returns, and acquisition cost. Two stores can have identical gross margins and wildly different unit economics once CAC and repeat behaviour are factored in.
Track both. First-order economics tell you whether you can scale spend without burning cash on the way in. Lifetime (or 12-month cohort) economics tell you the true profitability of the customer relationship. Decisions made on lifetime numbers alone tend to over-invest in channels with long, uncertain payback.
Returns hit twice: you lose the revenue and you still eat the outbound shipping, return shipping, and any restocking or write-down cost. For apparel especially, a 25% return rate can quietly turn a 50% gross margin into a 32% contribution margin. Always model returns net, not gross.
For online retail, 3-6 months on a 12-month cohort basis is healthy. Under 3 months is exceptional and usually signals strong organic or repeat. Over 9 months means you're financing growth — viable if cash is cheap, dangerous if it isn't.
LTV:CAC is one expression of unit economics, framed as a ratio. A 3:1 LTV:CAC is the common rule of thumb, but it hides timing — a 3:1 ratio over 36 months is far worse than 3:1 over 12 months because the cash is locked up longer.
The P&L mixes new-customer acquisition cost with revenue from existing customers acquired in prior periods. Unit economics isolates a cohort, so it shows whether the customers you're acquiring today will actually pay back. A profitable P&L can mask deteriorating unit economics for 12-18 months.
No — that's the point. Unit economics measures the marginal contribution of one more customer, which is what determines whether scaling spend is profitable. Fixed costs (rent, salaries, software) are covered by the aggregate contribution, not allocated per order.
Monthly at minimum, weekly during peak season or when scaling spend. The inputs drift constantly — auction costs, return rates, shipping carriers, AOV mix — and a number that was true in Q2 can be wrong by Q4. Tie the recalc to your media planning cycle.
Significantly. Branded search customers often have 2-3× the contribution of Meta prospecting customers — lower CAC, higher AOV, better repeat. Always cut unit economics by channel before making allocation decisions; the blended number hides where you're actually making and losing money.
Only if there's a credible, time-bound path to positive — usually through scale-driven cost reduction, repeat improvement, or a planned mix shift toward higher-margin SKUs. Negative unit economics without that path is a structural problem, and more marketing budget makes it worse, not better.
Track CAC, channels, and funnel conversion in one place
Metricuno connects ad spend, funnel events, and revenue so you can see CAC by channel, cohort, and campaign — without stitching together five tools.