Lably
Skip to content

Cross-device tracking

Tracking of users between different devices

  • 16 min read
  • 4 chapters

Related on Lably

Through Advertising, Internet of things and Sound

Cross-device tracking is a technique in which technology companies and advertisers deploy trackers, often in the form of unique identifiers, cookies, or ultrasonic signals, to generate a profile of users across multiple devices. Cross-device tracking can use audio beacons, or inaudible sounds, emitted by one device and recognized through the microphone of the other device.

This form of tracking is used primarily by technology companies and advertisers who use this information to piece together a cohesive profile of the user. These profiles inform and predict the type of advertisements the user receives.

Background

Online tracking can be performed in many ways. One historical method used website sign-ins to associate activity with an account. This is a form of deterministic cross-device tracking, in which the user's devices are associated with their account credentials, such as their email or username. While the user is logged in, the company can access a history of websites visited and ads the user interacted with across computers and mobile devices.

Cookies were later deployed by advertisers, providing each user with a unique identifier in the user's browser so that the user's preferences could be monitored. This unique identifier informs the placement of relevant, targeted ads the user may receive. Cookies were also used by companies to improve the user experience, enabling users to resume activity on websites. However, as users began using multiple devices—up to around five—advertisers had difficulty tracking, managing, and consolidating this data across multiple devices as the cookie-based model suggested that each device—whether a phone, computer, or tablet—was a different person.

Other technologies such as supercookies, which stay on computers long after the user deletes their cookies, and web beacons, which are unique images from a URL, are also used by trackers and advertisers to gain increased insight into users' behavior. However, advertisers were still limited in that only one device was able to be tracked and associated with a user.

Cross-device tracking initially emerged to associate a user's activity across multiple devices with a single profile.

Browser fingerprinting can be used to identify users based on distinctive browser and device characteristics. It has raised privacy concerns because of its effectiveness and because users may have limited ability to opt out of this type of tracking.

Google's AdID can be used on smartphones in combination with cookies on a user's computer to track behavior across devices.

One cross-device tracking method uses audio beacons, or inaudible sounds, emitted by one device and recognized through the microphone of another device, usually a smartphone. Cross-device tracking has also been discussed in relation to the Internet of things (IoT), in which devices such as office equipment, cars, and home appliances are connected through the internet.

Sign in to keep reading

3 more chapters are free with a Lably account.

More in Computing and communication