What are unit economics, and why do investors care so much?
Quick answer
is simply the money you make and spend on one customer (or one unit). It tells you if you make money on a single sale — because if you lose money on one, growing just loses money faster.
The mistake most founders make
Assuming scale will fix bad economics. It won't. Growth is a multiplier — it magnifies whatever your per-sale reality is. Founders chase growth hoping to “become profitable later,” then find later never comes, because each sale was losing money all along.
The four numbers
(cost to win a customer) = total sales and marketing spend ÷ new customers. (what a customer is worth over time) ≈ (revenue per customer × margin %) ÷ how fast they leave. = revenue per sale – the variable cost of that sale. = how many months of that customer's payments it takes to earn back what you spent to win them. Together they answer: do you make money on a customer, and how quickly?
What “good” looks like
As rough guides: you want a customer to be worth at least 3x what it cost to win them (below 3x you're buying sales at a loss; way above 5x you might be spending too little on growth), and you want to earn back your cost to win within 12 months. Healthy margin depends on the business — 70–85% for software, 30–60% for product/D2C, much lower for trading. And watch : if 5% of customers leave every month, your average customer only stays about 20 months, which quietly shrinks their value.
Our honest take
Fix the single sale before you pour money into growth. Good unit economics is what turns your raise from “trust our vision” into “back our math.”