A company can show a healthy operating margin while losing money on a third of its customers. Company-level financials average everything together. Unit economics pull the average apart and show which units — a client, a contract, a billable hour, a subscription — create value and which destroy it.
Pick the unit
The unit is the thing you sell repeatedly.
- Professional services: the billable hour, the engagement, or the client relationship
- Software as a service (SaaS): the subscription, usually measured per customer or per account
- Healthcare practice: the visit or the patient-year
- E-commerce: the order
Everything below is measured per unit.
Service business metrics
Realized rate
Revenue collected divided by hours worked on the engagement. Not the rate on the proposal — the rate you actually got after scope creep, write-offs, and discounts.
Utilization
Billable hours divided by available hours, per person. Track it monthly. A senior consultant at 55% utilization is a pricing problem or a sales problem, not a performance problem.
Contribution margin per engagement
Revenue minus direct labor cost (fully loaded, including benefits and payroll tax) minus direct expenses. This is the figure that tells you whether an engagement paid for itself before overhead.
Client concentration
Percentage of revenue from the top one, three, and five clients. Above roughly 25% from a single client is a risk that lenders and buyers will price.
SaaS metrics
Customer acquisition cost (CAC)
Total sales and marketing spend in a period divided by new customers won in that period. Include salaries, commissions, tools, and advertising.
Gross-margin-adjusted lifetime value (LTV)
Average monthly revenue per customer, multiplied by gross margin percentage, divided by monthly churn rate. Using gross margin rather than revenue is essential — hosting and support costs scale with customers.
LTV to CAC ratio
The central SaaS ratio. Below roughly 3 to 1, growth consumes cash faster than it creates value. Confirm the benchmark relevant to your segment.
CAC payback period
CAC divided by monthly gross profit per customer. Measured in months. It tells you how long your cash is tied up in each new customer.
Net revenue retention
Revenue from a cohort of customers twelve months ago, including expansion and net of churn and contraction, divided by that cohort's revenue twelve months ago. Above 100% means existing customers grow without new sales.
A worked example: services
A $6M consulting firm, 30 consultants. Company gross margin: 42%. Reasonable on the surface. Broken down by client:
- Top 12 clients: 51% contribution margin
- Middle 20 clients: 38%
- Bottom 15 clients: 9%
The bottom 15 accounted for 22% of hours and 6% of contribution. Three had negative margin after fully loaded labor — the firm paid to serve them. The fix was not to fire clients but to reprice or restructure the bottom tier, which lifted company gross margin to 47% within two quarters.
A worked example: SaaS
A $3M annual recurring revenue software company:
- Average revenue per customer: $400 per month
- Gross margin: 75%
- Monthly churn: 2.5%
- CAC: $6,000
LTV = $400 × 0.75 ÷ 0.025 = $12,000. LTV to CAC = 2 to 1. CAC payback = $6,000 ÷ ($400 × 0.75) = 20 months.
The company was growing 60% a year and celebrating. The unit economics said every new customer cost $6,000 and returned $12,000 over roughly three years — acceptable only if churn held, and 20 months of payback meant the growth was cash-negative for the foreseeable future. Reducing churn to 1.5% moved LTV to $20,000 and changed the entire capital plan.
How to report it
One page, monthly, same layout every time:
- Each metric with current month, prior month, and trailing twelve months
- One line of commentary per metric only when it moved
- The unit-level breakdown (by client, by cohort) as an appendix
What to do this quarter
- Choose your unit and define each metric in writing so it is computed the same way every month.
- Compute contribution margin by client or cohort for the last twelve months. Rank them.
- Address the bottom decile: reprice, restructure, or exit.
- Put the one-page unit-economics report on the monthly leadership agenda.