What metrics to track at each stage of the marketing funnel and how to calculate cost-per-retained-client.
Law firms measure a lot of marketing metrics: cost-per-click, impressions, click-through rate, cost-per-lead. But most of these metrics don’t tell you what actually matters—which marketing activities drive retained clients.
Think of your marketing as a funnel with multiple stages:
KPI: Traffic growth month-over-month
KPI: Cost-per-engagement (total marketing spend / total engagements)
KPI: Cost-per-qualified-prospect (total marketing spend / qualified prospects)
KPI: Cost-per-client (total marketing spend / new clients)
KPI: Cost-per-retained-client (total marketing spend / clients still active after 1 year)
Most agencies report on Stage 1 & 2 metrics. Maybe Stage 3.
The only metric that matters for your business is cost-per-retained-client.
If your cost-per-retained-client is $400 and your average case value is $5,000, your ROI is 12:1. That’s healthy.
If your cost-per-retained-client is $2,000 and your average case value is $2,500, your ROI is 1.25:1. That’s a problem, even if your cost-per-click metrics look great.
The same framework applies to each channel:
This tells you which channels are actually worth your investment.
Example: You spend $10,000 on Google Ads in Q1. You get 50 leads. 20 become clients. 15 are still clients one year later.
Cost-per-retained-client = $10,000 / 15 = $667 per retained client
Work backwards from your financial goals:
If a channel can’t hit your target KPI at scale, it’s not worth the investment.
This is how you align marketing spend with actual business outcomes.
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