Unit economics refers to the direct revenues and costs associated with acquiring and serving a single customer (or unit of product). It is used to assess whether a business is fundamentally profitable at the customer level — a critical question for investors evaluating scalability. A business can grow rapidly while destroying value at the unit level; good unit economics are what make growth worth funding.

The two most commonly cited unit economic metrics are Customer Acquisition Cost (CAC) and Customer Lifetime Value (LTV). CAC is the total fully-loaded sales and marketing cost required to acquire one new customer — including salaries, commissions, advertising spend, and tools — divided by the number of new customers acquired in a period. LTV is the total net revenue a company expects to earn from a single customer over their entire relationship with the company.

LTV for subscription businesses is typically calculated as: LTV = (Average Revenue Per Account × Gross Margin %) ÷ Monthly Churn Rate. A SaaS company with $400/month ARPA, 75% gross margins, and 2% monthly churn has an LTV of $15,000 per customer.

The LTV:CAC ratio is the standard investor benchmark. A ratio of 3:1 or better — meaning a customer generates at least three times what it cost to acquire them — is generally considered healthy for a SaaS business. Ratios below 1:1 mean the company is destroying value on every customer it acquires. Ratios above 5:1 sometimes signal underinvestment in growth.

The CAC payback period — how many months of gross margin are needed to recover the cost of acquiring a customer — is often more actionable than LTV:CAC at early stages, where churn assumptions are unreliable. The benchmark for efficient SaaS businesses is under 18 months. Payback periods under 12 months give investors confidence that growth can be funded through operating cash flow at scale.

At seed stage, founders are not expected to have perfect unit economics — but they should have directional clarity. Even rough cohort data showing that early customers have positive gross margins and acceptable retention is meaningful. Presenting unit economics in a pitch deck signals financial maturity and demonstrates that founders understand the economics of the business they're building. Investors will model it anyway — presenting your own version gives you the opportunity to shape the narrative.