Let’s say you run an employment law firm that represents employers. Your buddy who owns a residential HVAC company tells you billboards on I-95 are working great for him. You’re thinking: “If it works for him, it’ll work for me.”
Here’s where the math actually starts.
Billboard on I-95 near Savannah. You’re looking at 89,000 cars per day, averaging 1.55 people per car. That’s roughly 138,000 impressions daily, or 3.86 million impressions per 4-week period. The cost? $3,000 per 4-week period, plus $1,350 for vinyl installation upfront. That’s $4,350 for your first period, then $3,000 every four weeks after that.
Annual cost: $40,350 for 13 billing periods.
Your CPM (cost per thousand impressions)? Around $0.78 after the first period.
Sounds incredible, right?
Now let’s run the real math.
Your highest-converting audience is business owners and HR directors dealing with employment disputes. That’s roughly 0.8% of traffic on I-95. Maybe 1% if we’re generous.
Per 4-week period, you’re reaching:
- Total impressions: 3,862,600
- Your actual audience: 30,901
Your actual CPM for reaching decision-makers isn’t $0.78. It’s $97 per thousand people who could actually hire you.
Annually, you’re spending $40,350 to reach your target audience 401,713 times. That’s a real annual CPM of $100.
But your buddy’s HVAC company? Their highest-converting audience is homeowners age 35-65 with household income above $75K. That’s 28% of I-95 traffic.
Per 4-week period, he’s reaching:
- Total impressions: 3,862,600
- His actual audience: 1,081,528
His real CPM is $2.77.
Annually, he’s spending $40,350 to reach his target audience 14 million times. That’s a real annual CPM of $2.88.
Same billboard. Same price. His math works. Yours doesn’t.
This isn’t billboards being bad – we love billboards. They’re phenomenal when the math works. For the pediatric practice trying to attract young families? Billboard math works beautifully because 31% of that I-95 traffic is their highest-converting audience – that’s a real CPM of $2.51. For the employment law firm? You just paid $40,350 annually for 50.2 million wasted impressions to reach 402,000 decision-makers.
And here’s what makes it worse for you: with a billboard, you get zero attribution. Most business owners will never know which of those 402,000 annual impressions actually converted into clients. You’re flying completely blind for 13 billing periods.
Compare that to programmatic targeting at $12 CPM where we’re reaching only business owners and HR directors, with:
- Device-level tracking showing exactly who converted
- Daily creative optimization based on what’s working
- Segmentation by intent level – are they actively researching employment attorneys right now, or are we building awareness for when they need one?
- Household income filters ensuring we’re targeting companies that can afford your services
- Geographic precision reaching only your service area
Same annual budget. One approach has you paying $97 CPM with zero attribution. The other has you paying $12 CPM with complete visibility into what’s working. Also, they’re being exposed to not just one ad, but streaming TV commercials, streaming audio spots, and animated ads on websites.
This is the difference between copying what works for someone else and doing the math for your specific business.
Comments are closed