Digital out-of-home and privacy: a primer

Digital out-of-home and privacy: a primer

Samantha Brault  |  

Online advertising has long been a target for privacy advocates. Between activity tracking, ads that seem to follow you everywhere you go, and lingering fears that big data companies are reading emails or listening to conversations, there has been plenty of mistrust for online marketing. Not all of it is undeserved.

By virtue of the fact that digital out-of-home is in the category of digital marketing, it, too, has gained the suspicion of privacy advocates. Fortunately, DOOH audience data tracking is different from what is done online, meaning many of those concerns are greatly reduced, if not eliminated.

DOOH’s “semi-anonymity,” explained

DOOH audience data is collected and stored in a state of semi-anonymity. This means that while audience data is tracked, no individual’s personal information is ever stored.

To illustrate the concept, here’s a comparison between online targeting and DOOH targeting.

Tim uses his phone to go to his favourite blog, and he sees an ad for a new laptop. After clicking on the ad, he’s sent to an online retailer’s website. He then browses the retailer’s site, looking at a number of different products before closing his window.

These activities are all logged and transmitted to online advertisers, who, among other things, now know:

  • That Tim was on his favourite blog
  • That he saw and clicked on an ad for a laptop
  • What he looked at after clicking on the ad

This data can now be used to serve Tim more targeted advertising. When Tim goes back to his favourite blog, or to other websites that serve ads, he’ll be more likely to receive ads relating to the laptop he initially clicked on an ad for, as well as for the other products he looked at after. Tim’s phone is recognized online as a unique device, so his information gets tied to his unique online identity.

A man looking at his smartphone outside. Advertisers use browsing history to target their ads.

Personal electronic devices collect personal information that facilitates individual ad targeting

With DOOH, things are a little different.

Suppose Tim goes to the mall to check out that laptop in person at the electronics store. On his way through the mall, he sees a digital sign, and he pauses in front of it. He watches as an ad for a leather jacket, and then an ad for wireless headphones, play on the screen. When an ad for a luxury car plays, he walks away.

Throughout this process, it is likely that some data about Tim have been collected. The way that this is accomplished in DOOH varies tremendously across the industry.  Firstly, the mall owner has likely counted Tim and all foot traffic with simple IR sensors placed near the entrances. Over time, this helps the mall owner build a very good picture of the traffic patterns at certain times and days of the year. In transit, equivalent data is collected by turnstiles. In Cinema, it’s ticket sales. In outdoor, measurement companies like Geopath, Route, Nielsen and COMMB use sampling and statistical models to fulfill the role of measuring the total traffic in front of a screen at any given time.

Many DOOH operators also use real-time sensors at the screen level.  Across the industry, these sensors come in two main flavors: anonymous video analytics and WiFi detection.

Anonymous video analytics software uses a webcam and video analysis algorithms to see how many people are in front of the screen, whether or not they looked, and basic demographic information like age or gender. WiFi detection counts the number of WiFi-enabled devices passing in front of the screen. This type of measurement can be a good proxy to determine the amount of people exposed to an ad. With both visual data and WiFi detection, all sensor-level data is anonymized before analysis. Nothing personally identifiable is retained or transmitted to the cloud.

Lastly, many forward-thinking DOOH operators also invest in acquiring mobile location data (from exchanges and/or mobile SDKs).  This data originates from smartphones and can provide the types of hyper-specific audience segments online buyers are used to targeting.  However, this data is sent very infrequently from devices, in the order of 10 to 20 times a day, so it cannot provide a picture of the total audience a screen has.  

By accumulating these different kinds of data over time for a screen, a complete but anonymized picture of the audience composition emerges. It’s possible to discover patterns of behaviour common to the demographics of people who look at a given sign. However, no unique identifiers are ever collected that can associate any of that data to Tim specifically.

The bottom line:

While DOOH audience data is collected, it is much less specific than online data, and does not result in specific campaigns being targeted to specific people. Rather, the data is collected to illuminate patterns in audience activity and preference that can be used to better target campaigns to appropriate audiences – not specific individuals.

An aerial view of a mall floor. People are blurred, implying that they are walking. Though their demographics may be recorded, no personal information will be.

Audience data collected for DOOH media is semi-anonymous, meaning no personal details will be stored

The impact of GDPR on DOOH

The biggest data privacy story of recent years was the arrival of Europe’s General Data Protection Regulation (GDPR) and the many ways it would affect audience data collection and the delivery of campaigns. Email marketing and various other kinds of online advertising saw a drop in effectiveness in the wake of GDPR, leading marketing professionals around the world looking for effective alternatives — like DOOH.

So, how does GDPR affect the DOOH space?

Answer: It doesn’t. At least, not directly.

The anonymized nature of DOOH audience data means that DOOH audience data falls outside the scope of GDPR. If your business is all DOOH, all the time, you don’t need to worry about GDPR. If, however, your network somehow draws on data from other channels, like mobile, location or social media, it would be worth taking a moment to ensure you have adequate permissions to draw on those data sources. Even then, only those networks that are either located in the European Union, or that somehow incorporate data from users in the EU, will be directly affected by these regulations.

All in all, the fact that GDPR touches so lightly on the DOOH space means that DOOH is increasingly touted as a good replacement for those online channels that are now more heavily regulated.

A digital poster in Warsaw, Poland. It is on the side of the street at nighttime, and displays an ad for the Adele album "25."

GDPR doesn’t directly affect DOOH, making DOOH a good alternative to newly restricted digital channels

DOOH, visual data, and consent

Despite the fact that DOOH networks don’t capture or store information about individuals, there are some types of DOOH data collection that may still turn consumers off. In 2018, it became national Canadian news when facial recognition technology was found to be hooked up to digital info screens located in some of the country’s largest malls. A backlash led to the company that owns those malls promising to cease using the technology for the time being.

This highlights a challenge for network operators today. Where online users generally have some understanding of the fact that their activity is being tracked, it may be less commonly known that tracking is conducted in real-world spaces as well. Some individuals may be unhappy that they were not asked for consent for that tracking to be conducted, and still others may be wary of this kind of technology being used in publicly accessible spaces at all.

A digital sign advertising fashion products with a man walking by. Not everyone understands that they are being tracked by many digital signage installations.

Finding ways to communicate audience data tracking will be an important challenge for DOOH operators

Despite striking perhaps the best balance between utility and privacy of any of the major corners of the digital analytics world, there remain concerns by some people about what kind of digital signage audience analytics are collected, and how. Finding ways to more fully communicate what data is tracked and stored by digital signage software will help network operators better manage consumer expectations and avoid unpleasant surprises for privacy-focused individuals.

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