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.

The Funnel Metrics

Think of your marketing as a funnel with multiple stages:

Stage 1: Awareness

How many people are aware of your firm?
Tracked by: impressions, reach, website traffic

KPI: Traffic growth month-over-month

Stage 2: Engagement

How many aware people are interested enough to engage?
Tracked by: click-through rate, form completions, phone calls

KPI: Cost-per-engagement (total marketing spend / total engagements)

Stage 3: Qualification

How many engaged people are actually qualified prospects?
Tracked by: intake qualification rate, attorney consultations

KPI: Cost-per-qualified-prospect (total marketing spend / qualified prospects)

Stage 4: Conversion

How many qualified prospects become clients?
Tracked by: retainer signings, case acceptance rate

KPI: Cost-per-client (total marketing spend / new clients)

Stage 5: Retention

How many clients are still clients after 1 year?
Tracked by: client retention rate, repeat business

KPI: Cost-per-retained-client (total marketing spend / clients still active after 1 year)

The Most Important Metric

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.

Tracking by Channel

The same framework applies to each channel:

SEO: Cost-per-retained-client from organic search
Google Ads: Cost-per-retained-client from Google Ads (not just cost-per-click)
Directories: Cost-per-retained-client from directory referrals
Referrals: Cost-per-retained-client from attorney referrals (yes, even referrals have a cost—your marketing spend on relationships)

This tells you which channels are actually worth your investment.

How to Calculate It

Track total marketing spend by channel for a period (quarter or year)
Track all leads from that channel into your CRM
Track which leads became clients
Track which clients are still retained after 1 year
Divide total spend by retained clients

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

Setting Your KPIs

Work backwards from your financial goals:

How many retained clients do you want this year? (Example: 30)
What’s your marketing budget? (Example: $20,000)
What can you spend per retained client? ($20,000 / 30 = $667)
Set channel KPIs that achieve this.

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.

Marketing KPIs for Law Firms