Customer Acquisition: Cohort Cost and First-Job Contribution

Method and interpretation

Use a first-inquiry cohort with start ≤ end ≤ observation date. All dates use whole calendar days. Each row represents one channel under a declared assignment rule. Count unique first journeys, not repeat appointments. Stage counts must be nonnegative whole numbers and descend from inquiries to qualified leads, first bookings, first completions and new paying customers.

Cost and contribution

Included acquisition cost = media + agency + sales effort + other acquisition cost. Cost per inquiry, booking, completion or new paying customer divides that cost by the corresponding count. Zero denominators display “Unavailable,” retaining all spending and any loss. Stage rates use the immediately preceding stage as denominator. These are descriptive ratios, not causal conversion estimates.

Net first-job receipts = receipts before refunds − refunds, excluding pass-through tax. First-job contribution = net receipts − entered direct job cost. After-acquisition contribution = first-job contribution − included acquisition cost. Direct job cost must cover the same stated delivery population, including unpaid completions. Common overhead, repeat jobs, later lifetime revenue, financing, tax and capacity effects are excluded unless explicitly in the appropriate cost scope. Negative results remain visible.

Scope and overlap

Each row’s complete/partial flag is a user assertion. Partial cost still produces an entered-cost ratio with a warning. Combined totals appear only after an explicit declaration that customers, costs and receipts do not overlap. That declaration does not audit the inputs. Refunds above receipts remain permitted and flagged for a population/timing review.

Worked example

Two hypothetical channels have $3,600 / 12 = $300 and $2,500 / 10 = $250 cost per new paying customer. Net receipts of $9,000 and $6,800, less $3,600 and $3,500 delivery costs and acquisition spending, leave $1,800 and $800. Declared nonoverlapping total: $6,100 / 22 = $277.27 and $2,600 after-acquisition contribution. None of these amounts is lifetime value or verified EBITDA.

Validation and review

One to twenty unique channel references, valid dates from 1900–2200, counts up to 100 million and each nonnegative monetary input up to $1 trillion are supported. Missing, nonfinite, negative or inconsistent fields are rejected. Local CSV import requires the exact fourteen-column example header and a file under 2 MB. It replaces rows after structural checks, retains global dates and declaration, and requires recalculation. Reconcile the original records, unmatched population and shared cost allocation before making an operating decision.

Platform context: Google’s qualified/converted lead definitions. These configured events do not independently verify paid customers. Use the companion guide for the full evidence workflow.

Primary references

This numerical framework is explained in the companion guide. Contract, accounting and transfer conclusions require the actual evidence and appropriate review.