Digital Out-Of-Home (DOOH) advertising requires a unique approach to audience measurement, fundamentally different from traditional digital advertising. In this article, we break down the methods used to estimate the impact of a DOOH campaign, with a focus on a key concept: the impression multiplier.
Unlike online advertising where 1 impression = 1 person, DOOH operates on a collective exposure model. A single play can reach multiple people at once, making the impression multiplier essential.
Concrete examples:
Times Square: 1 play = ∼ 1,000 potential impressions
Shopping mall (Saturday): 1 play = ∼ 10 impressions
Gym (4 AM): 1 play = ∼ 0.5 impression
"This multiplier is what makes DOOH unique. When you buy a play, you're buying the chance to reach several people simultaneously. That's the strength of the medium." — 💬Dimitri, CEO of glooh
The Cost Per Thousand (CPM) in DOOH must be evaluated differently. The unit cost of a play is offset by the volume of impressions it generates.
Example:
1 play at €10 =
Traditional digital: 1,000 impressions → CPM = €10
DOOH Times Square: 100,000 impressions → CPM = €0.10
DOOH Gym (at night): 500 impressions → CPM = €20
Foot traffic counters
Point of sale or club badge scans
Gas station transactions
"These simple methods work well for local networks. They offer a clear and actionable view of audience potential." — 💬 Max, CPO at glooh
Wi-Fi / Bluetooth sensors
Anonymized cameras
Motion sensors
Organizations like CIM (Belgium) or ROUTE (UK) use databases combined with:
Viewing distance
Screen size
Travel speed
GPS and telecom data
Let’s take a screen in a shopping mall:
Average traffic: 1,000 people/hour
Multiplier: 3
1-hour campaign, 1 play every 2 minutes = 30 plays
Potential impressions: 30 x 3 = 90
Estimated real visibility (VAI 70%): 63 effective impressions
"The multiplier is crucial for calculating ROI. The same budget can have a very different impact depending on location and timing." — 💬 glooh Team
Large screens: high impact (branding)
Targeted screens: engagement and performance
Premium placements can have very favorable CPMs despite higher per-play cost
Understand the multiplier for each screen
Consider hourly traffic fluctuations
Combine screen types
Validate audiences with reliable methods
Want to try DOOH with glooh?
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