What is cross-device tracking?
Cross-device tracking is a marketing strategy that tracks users across multiple devices, such as their phones, smart TVs, tablets, and personal computers. Marketers use cross-device tracking to create user profiles across their devices, helping them understand the customer better and target them more effectively.
However, cross-device tracking is questioned by cybersecurity experts because of the lack of transparency and privacy.
Cross-device tracking involves several techniques — such as cookies, tracking pixels, and fingerprinting — linking user activity across multiple devices. Perhaps the most concerning approach is using ultrasonic beacons — inaudible sounds with encoded data through which a listening device can receive information. Humans can’t hear these sounds because their frequency is too high (generally above 18 kHz), but they can be detected by various smart devices (like your phone or laptop).
For example, you may be watching TV when an ad for toothpaste comes on. Without you knowing, the TV ad contains embedded ultrasonic beacons. While the ad plays, your phone’s microphone listens to the beacons (if it has the right permissions). You pick up the phone, go on social media, and see the same ad you’ve just seen on TV. Coincidence? No, just highly advanced and elaborate marketing.
NordVPN survey: Cross-device tracking is widespread
A recent survey commissioned by NordVPN in 11 countries showed that cross-device tracking involving ultrasonic beacons is widespread. Over half of the American respondents (53%) said they had noticed ads on their devices for a product/service they recently spoke about or saw on TV but had not searched for on that device. In the UK, 45% of respondents noticed such ads, while in Canada and Australia, 33% and 37% noticed them respectively.
People feel “followed” by their devices
Of those who noticed these ads after talking about a topic or seeing the same ad on TV, a high proportion reported feeling “followed”:
- 49% (UK)
- 46% (Canada)
- 42% (Australia)
- 39% (the U.S.)
Interestingly, 13% of UK respondents also reported feeling “scared” after noticing these ads. In comparison, 20% of American and 17% of Australian respondents said they were “happy” because they were shown ads about something they were interested in. These results highlight the contrasting outlooks toward targeted advertising in different countries.
Twelve percent of Americans also said they felt “special/important” after seeing these targeted ads — but this sentiment wasn’t echoed in other markets.
Tracking is most noticeable on smartphones
When asked what devices they noticed targeted ads on after talking about a topic or seeing an ad on TV, the majority of respondents said it was their smartphone:
- 81% (UK)
- 77% (Australia)
- 77% (the U.S.)
- 76% (Canada)
Additionally, 52% of respondents in the U.S. noticed it on their computers (50% in Australia and 49% in Canada). Interestingly, only 33% of UK respondents noticed these targeted ads on their computers.
Many users don’t know they can restrict permissions
When asked whether respondents were aware that they could restrict their phone’s permissions and stop them from listening, the majority of respondents in Australia, Canada, and the UK said they weren’t:
- 65% (Australia)
- 65% (Canada)
- 62% (UK)
In the U.S., 50% of respondents said they were aware they could change their phone’s permissions. Though this percentage is lower than in other English-speaking countries, it still shows that half of the American respondents don’t know they can protect themselves from this type of tracking.
How can you reduce cross-device tracking?
The idea of your devices tracking you without your knowledge and communicating with one another to show you targeted advertising is unnerving. However, the good news is that you can take several steps to limit cross-device tracking and gain more control over your privacy. Here’s how to reduce cross-device tracking:
- Review your app permissions. You can’t stop ultrasonic beacons from emitting sound frequencies around you. However, you can restrict your devices from listening. Check the permissions you’ve given the apps on your phone, and be mindful of permissions to access your microphone. For example, does your Google Chrome app need access to your microphone? If not, change the app permissions to give yourself more privacy.
- Use a VPN. While a VPN won’t stop your phone from listening to you, it will enhance your overall digital privacy and security. A VPN secures your internet traffic with encryption and masks your IP address, hiding your internet activity from your internet service provider, governments, and other third parties. On top of that, NordVPN now offers Threat Protection — an advanced cybersecurity feature that blocks malicious URLs, annoying ads, and web trackers.
NordVPN surveyed 10,800 respondents in 11 countries: Australia, Canada, Germany, Spain, France, Italy, the Netherlands, Poland, Sweden, the UK, and the US. An external agency conducted the surveys between 23rd February and 7th March 2023. Respondents were asked a set of questions about advertising and cross-device tracking. The samples were representative of the adult population of the respective country (18+).