Unit economics
In short
Unit economics is the money a business makes or loses on each single unit it sells, such as one customer, one subscription or one AI query. It shows whether growing bigger makes a company more profitable or simply loses more money.
- Also called
- Per-unit economics, Unit margin
- Topic
- The AI business
- Level
- Some background helps
The idea is simple: strip a business down to one sale and ask whether that sale makes money once the cost of delivering it is counted. Investors look at it closely in subscription businesses, where headline revenue can look healthy while each customer is unprofitable1.
Two common measures are customer acquisition cost (CAC), the full cost of winning a customer, and lifetime value (LTV), the present value of the future net profit from that customer1. Gross margin, revenue minus the direct cost of providing the product, shows how profitable each sale is1.
AI changes the sums. Traditional software costs almost nothing extra to serve one more user. AI products pay for computing on every request. In 2020 the investors Martin Casado and Matt Bornstein of Andreessen Horowitz reported AI companies with gross margins "often in the 50-60% range", below the 60-80%+ typical of comparable software firms, because of cloud computing and human support costs2.
The pressure shows up at the largest firms. Microsoft said its cloud gross margin fell to 66% in the year to June 2026, driven by "continued investments in AI infrastructure and growing AI product usage"3.
This is why pricing matters so much in AI. A flat monthly fee can lose money on heavy users, which pushes vendors towards charging for usage.
Example
If a chatbot subscription costs £20 a month, but a heavy user's questions cost the company £30 a month in computing, that customer has negative unit economics. Signing up more people like them would deepen the loss.
Why it matters
It is the quickest test of whether an AI company's growth is real or subsidised. Fast revenue growth means little if every customer costs more to serve than they pay.
Questions people ask
What are good unit economics?
Broadly, a business has good unit economics when each customer brings in more profit over time than it cost to win and serve them. Investors often compare lifetime value, the present value of future net profit from a customer, with customer acquisition cost1.
Why do AI companies have worse margins than software companies?
Because every AI request uses paid computing. Andreessen Horowitz partners reported in 2020 that AI firms often had 50-60% gross margins against 60-80%+ for comparable software firms, citing cloud and human support costs2. Falling inference prices may narrow that gap.
What is the difference between unit economics and profit?
Profit is the whole company's result after all costs. Unit economics looks at a single customer or sale. A start-up can lose money overall while each customer is profitable, if it is spending heavily to grow. The reverse is a warning sign.