DOOH vs. OOH Measurement: How the Out-Of-Home Yardstick Has Evolved 

July 24, 2023

Compared to traditional out-of-home advertising, digital out-of-home (DOOH) offers much more precise measurement methods. Accurately measuring impressions and audience behavior after exposure helps advertisers make smarter decisions about their spend and increase ROI. 

However, 32% of marketers are unaware of the performance attribution capabilities of DOOH, according to Sightline’s The DOOH Difference Report. If that’s the boat you’re in, you’re not alone.  

In this post, we’ll break down how DOOH measurement has evolved from traditional methods and how its KPIs can help you choose the best placements for your advertising budget.  

DOOH vs. OOH measurement 

Because of their one-to-many nature, both OOH and DOOH rely on impressions as their main form of measurement. Impressions estimate the number of times an ad is viewed. This metric is the most common basis for pricing OOH inventory as well.  

In contrast to one-to-one advertising channels, such as online ads and social media, many people can view the same out-of-home ad in the same place at any given time. This adds a layer of complexity to measurement that traditional OOH and digital OOH each address in their own way.  

The digital nature of DOOH and its connected technologies drives the difference in accuracy between the two mediums.  

Below, we’ll take a closer look at these differences.  

Measuring traditional out-of-home advertising 

Traditional OOH ads, such as billboards and other static signage, use a mix of sources to estimate ad impressions. Historically, daily effective circulation (DEC) was used to estimate the number of people in vehicles who potentially saw an ad, based on data such as road traffic counts.  

Then in the early 2010s, The Traffic Audit Bureau (TAB), now known as Geopath, introduced its variable adjustment index (VAI) to refine DEC measurements. The VAI used data from driver eye-tracking experiments to estimate the percentage of people who instead likely looked at an ad.  

Combined with census data, consumer research, and ad characteristics such as size and distance from the road, the VAI provided more accuracy and audience insight than simple DECs and is still the standard for traditional OOH measurement today. Marketing tactics such as campaign-specific promo codes, microsites, and hashtags can be used to further track OOH effectiveness.  

Compared to the early days of billboard advertising, these innovations made measurement much more accurate for OOH advertisers. Enter: digital out-of-home.  

DOOH measurement methods 

Digital OOH advertising screens, such as those you see in stores or on sidewalks, can be enabled with different types of technology to provide a more accurate analysis of impressions and even account for real-time fluctuations. Because DOOH impressions can be verified, advertisers can be confident that they’re paying for real viewers.  

DOOH screens typically cycle through multiple ads on a loop. This is factored into measurement by using an impression multiplier to determine how many people see an ad each time it plays. The DOOH impression multiplier is unique to each screen in each media owner’s network.  

How are multipliers calculated? A few common methods include: 

  • Camera sensors: Sensors in ad screens record impressions, detecting people within viewing range, whether viewers are facing the screen, and for how long. This method is ideal for accurate measurement of verified impressions and dwell time. 
  • Mobile & GPS data: Mobile and GPS location data determines the number of people near a screen when an ad plays. This is useful for impression estimates and behavior tracking after exposure.  
  • Venue-specific counts: Venue-owned DOOH networks that measure foot traffic by tangible means, such as ticket sales or gate sensors, can provide accurate impression counts when the screens are near the action of tangible activity. 

DOOH media owners use these tools on a sample of screens in their network and then extrapolate from the data to offer accurate impression estimates across similar ad inventory. 

adPlanet’s grocery and retail DOOH network uses sensor technology developed by Quividi, double verified with Geopath data, to give buyers the most accurate representation of impressions across the fleet of screens nationwide. 

While debated among different measurement providers, camera sensors do have a key accuracy advantage that other methods struggle to contend with — genuine, real-time samples of real ad viewers. For location data methods, the waters are a bit murkier. Many DOOH networks that use geofencing do not specify the exact latitude and longitude of display screens, so mobile proximity is a looser estimate. 

Regarding consumer privacy, sensor technology has an edge over location data, as camera sensors do not store images of viewers; they only record data about each view. In contrast, GPS tracking stores mobile user data, albeit anonymized, and is more vulnerable to growing consumer privacy concerns. Additionally, mobile users’ ability to opt out of location tracking affects the accuracy and scalability of GPS methods. This privacy advantage of sensor measurement makes it more future proof than other methods.  

Sensor technology is the best method of DOOH measurement for media buyers looking to drive brand visibility and awareness, based on its higher accuracy of viewer measurement. Location data methods can be helpful for tracking behavior, such as website visits or online purchases, and retargeting after exposure. But keep in mind, even with other measurement methods, these types of actions can be monitored through creative efforts like microsites and QR codes.  

The differences between DOOH measurement methods are broken down further in the table below: 

DOOH Measurement MethodAdvantagesDisadvantages
Camera Sensors – Based on verified views 
– Most accurate impression counts 
– Best for brand awareness campaigns 
– Fewer attribution capabilities 
Mobile & GPS Data – Better attribution capabilities 
– Best for retargeting campaigns 
– Variations in impression accuracy 
– Affected by privacy policies and guardrails 
Venue-Specific Counts – Simplest to obtain – Only relevant to specific venue types 
– Impression accuracy varies by screen placement 

The buyers who advertise on adPlanet’s screens, many of which are CPG Fortune 500 brands, are focused on brand awareness and looking for the most reliable way to verify the impressions they pay for. Our approach to measurement with Quividi’s sensor technology, in combination with conventional traffic counts, provides extremely precise measures of impressions, dwell time, and genuine viewers.  

Accurate measurement also enables DOOH to account for unexpected fluctuations in impressions due to external factors, such as seasonality or market conditions. Advertisers can easily adjust their campaign strategy to align with those real-time measurements, which in turn improves advertising ROI.  

How accurate DOOH measurement benefits advertisers 

On top of a more reliable view of performance, advertisers also gain transparency and fairness in pricing when purchasing DOOH. This reliability, transparency, and fairness are undeniably linked.  

Digital OOH allows for programmatic buying options, where advertisers purchase placements through an automated demand-side platform (DSP). Inside the DSP, ad inventory is configured with its applicable impression estimates and multipliers, so buyers understand exactly how much exposure they are paying for.  

Programmatic DOOH is most often sold on a CPM model, priced per thousand impressions. Because DOOH owners are able to calculate impressions with so much precision, advertisers can be certain that they’re paying a fair CPM. Even for other pricing models, including share-of-voice and loop frequency, DOOH measurement technology can inform on decision factors such as viewer dwell time. 

You can see, especially within the context of ad buying, how important measurement accuracy is. As you explore which DOOH networks best fit your brand, consider how those publishers evaluate impressions and whether they fit your standard of accuracy. 

Make the most of your ad budget with DOOH 

Out-of-home advertising has come a long way over the last century, and now with digital OOH, it’s progressing like never before. While traditional OOH might still have its place in your strategy, DOOH’s innovative measurement capabilities deliver more value for your advertising dollars.  

Remember that different methods of DOOH measurement can be relevant to different brand or campaign goals. Media owners and buyers can benefit from a combination of measurement tactics to achieve the highest degree of accuracy and functionality.  

There’s a reason DOOH investment in the US grew by 39.6% in 2022 alone. The advantages DOOH offers marketers may be immeasurable, but DOOH itself is precisely and verifiably measurable.  

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