Billboard vs Car Wrap vs Online Ads: How to Compare the Cost

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CPM, cost per month and cost per tracked result: a practical way to compare billboards, car wraps and online ads that each measure themselves differently.

Comparing advertising channels by CPM (cost per thousand impressions) looks scientific. It usually isn't, because each channel counts an "impression" in its own way. Here's a comparison that holds up.

Why CPM comparisons mislead

So a vehicle "CPM of $0.40" against a social "CPM of $10" isn't really a comparison. It's two different definitions put next to each other.

A better comparison: three numbers

1. Cost per month of presence

How much it costs to be visible for a month, whatever the channel. It's the easiest number to get and the hardest to fudge.

2. What you can verify

Rank each option by the evidence you'll actually get: dated photos of the billboard, video of the car on the road, platform reports. Anything you can't verify, discount heavily.

3. Cost per tracked result

Give every channel its own vanity URL, promo code or landing page, and compare what it costs per visit, signup or sale that you can attribute. It's the only number that means the same thing across channels. Setting that up takes an afternoon.

What each channel is good at

ChannelStrengthWeakness
Online adsTargeting, instant tracking, switch on and offStops when spend stops, ad blindness
BillboardsScale, one location, a sense of legitimacyExpensive, fixed place, hard to attribute
Vehicle adsRepetition, local presence, long runsLoose metrics, glance-only creative
Stunts and storiesEarned coverage, shareabilityUnpredictable, one-off

The mix most small brands should run

Online ads to catch intent, plus one physical thing that makes the brand feel real. For most small budgets, that physical thing isn't a billboard. It's something with a story people want to share. That's the idea behind the Harrier.ev placements: a vehicle ad that is also a public experiment people follow.