How does audience measurement work in DOOH?

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.

The Impression Multiplier: What Makes DOOH Unique

A Core Concept

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

Impact on CPM

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

Audience Measurement Methods: From Basic to Sophisticated

1. Direct Methods (Small Networks)

• 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

2. Intermediate Technologies

• Wi-Fi / Bluetooth sensors

• Anonymized cameras

• Motion sensors

3. Advanced Methods (Institutes)

Organizations like CIM (Belgium) or ROUTE (UK) use databases combined with:

• Viewing distance

• Screen size

• Travel speed

• GPS and telecom data

Practical Example: Calculating Audience

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

Implications for Advertisers

Strategic Choices

• Large screens: high impact (branding)

• Targeted screens: engagement and performance

Budget and ROI

• Premium placements can have very favorable CPMs despite higher per-play cost

Best Practices

• Understand the multiplier for each screen

• Consider hourly traffic fluctuations

• Combine screen types

• Validate audiences with reliable methods

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For more:

• 8 Best Practices to Make Your DOOH Campaign a Success

• DOOH Glossary

• DOOH in France: Key Stats, Trends and Insights for 2024