How to Track Cost Per Case from Radio Advertising for Personal Injury Firms

Walk into most PI marketing directors' offices and ask what their radio spend costs per signed case. You will get one of two answers: a shrug, or a cost-per-lead number that stops well short of what you actually need to know. Radio is one of the largest line items in many PI advertising budgets—AM drive-time, sports radio, talk radio, Spanish-language formats—and it is among the hardest channels to attribute accurately.

The station will give you reach figures, listener demographics, and gross rating points. None of those metrics connect to a signed retainer. Without a deliberate attribution setup, radio becomes a faith-based budget line: you keep running it because “calls feel like they come in when we're on the air,” and you cut it during budget pressure because you can't defend it with data.

This guide covers the three-method attribution framework that connects your radio spend to signed cases—so you can calculate a real cost per case, benchmark radio against your other channels, and make budget decisions based on outcomes instead of intuition.

Why Radio Is Harder to Attribute Than Digital Channels

Digital channels have an inherent attribution advantage: a user who clicks a Google ad generates a session ID, a click timestamp, and a conversion event your CRM can capture. Radio generates none of that. A listener hears your spot during morning drive, thinks about it, and calls four days later when they finally decide to get legal help. The connection between the impression and the call is invisible unless you build a system to surface it.

Radio also has a longer intent-to-action cycle than most digital channels. A prospect who searches “personal injury attorney near me” is in active buying mode. A prospect who hears your radio commercial is in awareness mode—they may not need legal help yet. When they do, they reach for the phone number they remember. That delay is what makes radio attribution difficult and why a 30-day attribution window consistently undercounts radio performance.

Despite these challenges, radio attribution is achievable. The same frameworks used to track TV and billboard performance apply here: dedicated tracking numbers, structured intake questioning, and geo-lift analysis. Used together, they recover the majority of radio-attributed cases and produce a cost-per-case figure you can put on the same dashboard as your Google, Facebook, and aggregator numbers.

Method 1: Dedicated Tracking Numbers by Station and Daypart

The most direct attribution method is a phone number that exists exclusively in your radio advertising. When that number rings, the call is radio-attributed by definition.

Assign a unique CallRail number to each radio station you advertise on. If you run spots across multiple dayparts on the same station— morning drive and evening drive, for example—use separate numbers for each daypart. This lets you compare not just station performance, but time-of-day performance. Morning drive on a sports station may produce a very different cost per case than the same station's weekend programming.

A few rules that matter:

• Never reuse a tracking number across channels. A number that appears on both a radio spot and a direct mail piece cannot tell you which channel generated the call.
• Run the tracking number for the life of the attribution window. If you pull the number three weeks after a flight ends, you will miss calls from prospects who heard your spot but acted later. Keep radio tracking numbers live for at least 90 days after a flight.
• Include the tracking number in every creative.Spots that only mention a vanity URL (“call us at AccidentHelpNow.com”) redirect to digital and lose the radio attribution signal.

Method 2: Structured Intake Questioning

Tracking numbers capture direct-dial calls. They miss the prospects who heard your radio spot, searched your firm name, and called the website number. Structured intake questioning bridges that gap.

Every intake call should include a source question with a forced-choice dropdown—not a free-text field. Free text produces dozens of variations of “radio” (“heard it on the radio,” “radio ad,” “AM station”) that cannot be aggregated. A dropdown produces a clean tag.

Build your radio options specifically:

• Radio / AM Talk
• Radio / Sports (and name the station if you're on multiple)
• Radio / Spanish Language
• Radio / Other

When a caller says they heard you on the radio, intake tags the specific format. That tag flows through to the case record in your CRM, and eventually to your cost-per-case calculation. This method typically recovers an additional 20–30% of radio-attributed cases beyond what tracking numbers capture alone.

Method 3: Geo-Lift Analysis for Brand-Level Attribution

Some radio exposure converts through brand search rather than direct call. A prospect hears your name on the radio, searches it on Google, and clicks your website listing. That call shows up as branded search, not radio, in your standard attribution.

Geo-lift analysis compares your branded search volume and inbound lead volume during radio flight weeks against non-flight weeks in the same market. If you see a consistent 12–18% lift in brand search during active radio weeks, a portion of that lift belongs to radio. It is not precise attribution, but it provides a defensible estimate for the brand-building portion of your radio investment that tracking numbers and intake tags cannot capture.

This method requires at least three to four flight periods to establish a reliable pattern. Use it as a supplemental signal, not a primary attribution source. The tracking number and intake tag methods are your core data; geo-lift is the adjustment that prevents you from systematically undervaluing radio.

What Cost Per Case from Radio Actually Looks Like

PI firms with full radio attribution report a wide range of cost per case by format. Drive-time AM and PM slots on talk and news stations carry premium rates and typically produce cost per case of $3,500–$6,500. Sports radio—particularly local NFL and NBA affiliates during season—runs $2,500–$5,000 per case for firms in markets where the audience skews toward auto accident demographics. Weekend and off-peak programming runs less per spot but often produces higher cost per case because audience concentration is lower.

Spanish-language radio is an outlier worth tracking separately. In markets with large Hispanic populations, Spanish-language radio often produces cost per case well below the firm's overall average because competition is lower and conversion rates from bilingual intake teams are high. Firms that do not track Spanish-language radio separately bury that performance advantage in their blended radio number.

Why the 90-Day Attribution Window Is Non-Negotiable for Radio

The single most common mistake PI firms make with radio attribution is measuring it on a 30-day window. Radio does not work like paid search. A prospect who hears your spot during morning drive on a Monday may not be involved in an accident until the following month. When they call, they remember “that attorney I hear on the radio”— not a specific week or date.

PI firms with mature radio attribution programs consistently find that 35–50% of radio-attributed cases call after day 30 from their first exposure. A 30-day window cuts those cases out of your attribution. The result is that radio appears to produce fewer cases than it actually does, making it look more expensive than your other channels on a cost-per-case basis.

Run your radio cost-per-case calculations at 30, 60, and 90 days and watch how the cohort matures. The 30-day number will look discouraging. The 90-day number is usually the defensible one. If you use 30-day windows for all channels, at least be consistent—but radio will be the most systematically undercounted channel in your portfolio.

How Radio Fits Into Your Full-Channel Comparison

Once you have a cost-per-case number for radio, the comparison is straightforward. Tag every radio-attributed case in your CRM the same way you tag Google, Facebook, TV, billboard, and aggregator cases. Run the same cost-per-case query across all channels. Radio earns a line on the same dashboard—no more “brand awareness budget” exemptions.

For most PI firms, radio lands in the mid-range: more expensive per case than branded Google search and attorney referrals, less expensive per case than shared aggregator leads and Facebook Lead Ads. That relative position tells you where radio fits in a budget reallocation conversation.

If your radio cost per case comes in at $4,200 and your aggregator cost per case is $3,800, that does not mean you cut radio. It means you understand the trade-off. Radio provides brand awareness that compounds over time—it builds recall that makes your digital ads more effective and your referrals easier to close. The cost-per-case number is not the whole picture. It is the starting point for an informed decision, which is exactly what you cannot make without it.

Tracking radio the same way you track every other source is the foundation. RevenueScale's Source Intelligence layerpulls all channel data into a single cost-per-case view, including offline sources like radio, so your budget decisions are based on your actual portfolio—not the channels that happen to have easy digital tracking.

Start with One Station, Then Scale the Framework

If you are running radio across four stations and have no attribution infrastructure, do not try to build it all at once. Pick your highest-spend station and assign a dedicated tracking number this week. Add the radio source tag to your intake dropdown in the same conversation. Run that setup for 90 days and calculate your first cost-per-case number.

That single data point will tell you more about your radio investment than the last year of GRP reports from your stations. Once you have one station working, replicating the framework across the rest of your radio buy takes less than a week.

Radio advertising is one of the most powerful brand-building tools in PI marketing. It deserves the same measurement discipline as every other channel in your portfolio. The firms that build that infrastructure now are the ones who can defend their radio budgets—or reallocate them confidently—while competitors are still guessing.

If you want to see what a full-channel cost-per-case view looks like for your firm, book a demo and we will walk you through how RevenueScale connects your radio spend to signed cases alongside every other source you manage.