Choose The Outcome You Are Buying Toward
An inquiry, a connected call, a qualified prospect, a signed case, a booked job, and a retained customer are different measures. Choose the relevant outcome for the decision and preserve the earlier stages so you can see where performance changes.
For a law firm, cost per signed case can help assess acquisition performance, but it does not establish eventual case value, fees, timing, or profitability. Those require separate firm-owned information and assumptions.
Define The Cost Boundary
Media spending is only one possible component. Partner fees, agency or management costs, landing-page work, call handling, and intake labor may also affect the decision. Use the same inclusion rule when comparing sources or periods. If shared costs must be allocated, document how the allocation works.
Compare Mature Cohorts
A source generating inquiries this week should not automatically be compared with a source whose cases have had months to progress. Use an acquisition period, a defined observation window, and a consistent outcome definition. Identify duplicates, reopened opportunities, and missing records rather than silently counting them as new business.
Make The Calculation Useful
VG can help connect source and pipeline records, investigate differences, and translate the economics into resource decisions. Sometimes the next investment belongs in follow-up or capacity rather than acquisition. The calculation should make the tradeoff visible, with uncertainty stated clearly.