What Are Unit Economics?
Unit economics zooms in from the income statement to the smallest repeatable unit of the business. For a subscription company the unit is usually a customer; for a marketplace or delivery platform it is an order or a transaction. The question is always the same: after the direct, variable costs of serving that unit, does the company keep any money?
The core output is contribution margin per unit — revenue minus all variable costs, before fixed overhead such as corporate salaries and rent. A company with positive contribution margin can, in principle, grow into profitability as volume spreads fixed costs across more units. A company with negative contribution margin loses more money with every additional sale, and scale only deepens the hole.
How to Analyze Unit Economics
For subscription businesses, the analysis usually centers on lifetime value versus customer acquisition cost. An LTV/CAC ratio of at least 3x and a CAC payback period under roughly 18 months are the standard health markers, because together they imply each customer eventually returns a healthy multiple of what it cost to acquire.
For transactional businesses the math runs per order. A food delivery platform might collect $30 per average order but keep only $6 after paying the restaurant and the driver. Subtracting roughly $2 more for payment processing and customer support leaves about $4 of contribution, or 13% of the order value — enough to work, but only if order volume grows large enough to absorb marketing and corporate overhead.
Why Unit Economics Matter
Unit economics separates businesses that lose money because they are investing in growth from businesses that lose money because the model itself is broken. The 2010s produced several cautionary tales in ride-sharing and food delivery, where heavily subsidized transactions produced spectacular revenue growth alongside negative contribution per order. When capital markets tightened after 2021, investors shifted decisively toward companies that could prove profitable units.
In venture capital, growth equity, and private equity diligence alike, rebuilding a target's unit economics from raw data is one of the first workstreams, and interviewers often hand candidates a simple per-order or per-customer case to test the concept. Being able to define contribution margin and connect it to LTV and CAC is table stakes for those seats.
