The metric that matters
Cost per signed case: the only marketing number tied to signed clients.
Clicks, impressions, calls and even leads can all rise while your signed-case volume stays flat. Cost per signed case (sometimes called cost per retained case) is the one metric that connects what you spend to the clients you actually retain — and it's the number most agency dashboards never show.
How to calculate it
total marketing cost ÷ signed cases
"Total marketing cost" means everything: ad spend, agency and management fees, lead-purchase costs, and the attributable share of intake staff time. "Signed cases" are matters that produced a signed retainer — measured across your firm's real sales cycle (often 90–180 days for personal injury), not the calendar month the click happened in.
Cost per signed case calculator
Cost per signed case
$3,750
Annual marketing cost
$540,000
Illustrative estimate only. A true figure includes attributable intake cost and is measured across your firm's actual sales cycle. Not evidence of savings or recoveries.
Why cost-per-lead misleads law firms
A vendor can deliver cheap leads all day. If those leads don't sign, low cost-per-lead simply hides a high cost per signed case. Industry benchmarks put personal-injury lead costs anywhere from roughly $200 to $700+ per qualified lead — but the number that decides profitability is what each retained case costs after intake conversion. Two vendors with identical cost-per-lead can differ by thousands per signed case once you follow the leads through to retainer.
Cost-per-lead ranges cited from published 2026 legal marketing benchmarks (MadeForLaw, 2026). Figures reflect the broader market, not RetainProof clients.
Why most firms can't calculate it — and how it gets verified
Calculating cost per signed case requires closed-loop attribution: every lead source tagged, call tracking in place, and each matter's original source carried through intake to a "retained" status in your CRM. When that chain is broken — or when the only reporting comes from the vendor being paid — the number is difficult to verify. An independent review reconciles your spend, invoices, lead data and retained matters to calculate it from a neutral vantage point.