Cross-device tracking refers to technology and methods that help you track user behaviors across multiple devices by matching these devices with the user who owns them.
- As more people actively use multiple devices to engage with your company, you can use cross device tracking technology to get a complete picture of user activity across every device they use.
- A comprehensive view of user behavior across devices enables you to create seamless, omnichannel user experiences, tailor brand messaging to customer needs, and identify the best-converting channels.
- The most common cross device tracking methods are deterministic and probabilistic tracking.
What is cross-device tracking and why is it important?
Cross-device tracking collects and combines user behavior data across multiple devices, like desktop computers, laptops, tablets, mobile phones, smartwatches, and smart TVs. The goal of cross-device tracking is to create a full picture of a user’s journey as they switch between devices. You do this by linking the multitude of cross-device activities to the right user.
The average person switches between devices and platforms countless times a day. For example, a user first comes across an ad on TV, then sees a related Instagram ad on their phone, and finally uses their laptop to make the purchase. Without cross-device technology, all these activities would be counted as unique, separate visits not tied back to the same customer—which would result in an incomplete view of how and when the customer converted.
The need for accurate cross-device conversion tracking continues to increase as more people own multiple devices. According to Statista, the average number of devices per person globally in 2023 is approximately 3.6. And for the United States specifically, Deloitte reports that the average household now has 13 device types and 21 devices.
Not only do the devices grow in numbers, but they also become more connected. For instance, when you log into Chrome using the same Google account, you can access your saved passwords, bookmarks, and browsing history across every device.
This degree of synchronization allows people to seamlessly switch between devices without losing the continuity of their user experience. Cross-device tracking methods ensure these converging behaviors are captured correctly and account for how users behave across each platform and device.
Benefits of accurate cross-device conversion tracking
Cross-device tracking offers multiple advantages and enables product managers and marketers to get an in-depth view of how customers behave when they use different devices.
Cross-device conversion tracking helps companies to:
1. Get a complete view of the user's journey
In 2023, internet users globally spent 57 percent of their time browsing the internet on their mobile phones. So it’s no surprise that more customer-brand interactions occur on smartphones.
Companies that don’t use cross-device tracking and rely solely on cookies struggle to connect the dots between user activities happening on phones and computers. With increasing limitations on cookie tracking, only cross-device tracking can provide the depth of insight needed to understand user behavior across devices fully.
Cross-device tracking eliminates blind spots and helps you understand how customers engage with your website, mobile app, digital ads, and TV commercials at every step of the customer journey.
2. Identify the best converting channels and campaigns
Cross-device conversion tracking gives you a 360-degree view of every customer interaction with your brand. A clear understanding of user behaviors across devices translates into a better understanding of how and when users decide to convert, and what drives them to make a purchase or walk away.
Knowing which platform or promotion influences your users the most enables you to allocate your ad spend to the highest-converting campaigns and channels. You can also optimize or eliminate campaigns that aren’t performing well.
3. Map and personalize brand messaging
Once you gather enough information about a target group, you can start making data-driven predictions about their current and future behaviors. The insights you gather give you a more accurate understanding of the group’s preferences and the messaging that resonates with them most. Then cross-device targeting enables you to deliver users relevant messages when they are most ready to respond to them.
Moreover, users consume content differently on different devices. Cross- device advertising helps you tailor brand messaging to users' content consumption patterns. For example, if someone is quickly checking their social media on the go, you should present them with skimmable, attention-grabbing content. If they’re watching a long-form YouTube video on their laptop, a detailed product overview might be more appropriate.
How has cross-device tracking evolved?
Cookies have traditionally been the go-to approach for capturing and analyzing website traffic. They’re a digital tracking code placed on a user’s browser by the websites they visit. Cookies were effective for a long time, but increasing privacy regulations and consumer data privacy concerns have led to their demise.
A huge shortcoming of cookies is that they can only track user behavior within a single browser. As such, cookies cannot be shared or passed across browsers or devices. When you open a site link in Chrome and then open an identical link in Firefox, cookies can’t tie these events back to you as the same user and instead treats them as two separate instances.
Modern cross-device technology and tracking methods
So, how does cross-device tracking work? To answer this question, let’s explore different approaches to cross-device analytics.
Deterministic cross-device tracking
An alternative to cookie-based tracking appeared when companies began inviting visitors to sign into their websites and applications. This enables them to link each user’s device to their account credentials, like their username or email address. For example, when you sign into YouTube on your laptop and later sign into the mobile app, deterministic cross-device tracking recognizes you as one person or user.
Though practical and exact, deterministic tracking comes with certain limitations. It only works with past customers or registered users and doesn’t track new visitors without an assigned ID.
Probabilistic cross-device tracking
Probabilistic cross-device tracking relies on probability theory and complex algorithms to capture user activity across multiple devices. In the absence of identifiers such as email, mobile number, device ID, and user ID, or the ability to join them accurately due to other factors, you have to rely on signals rather than first-party identifiers.
Probabilistic tracking analyzes anonymous data points to identify which devices belong to the same user, including:
- IP addresses
- Device proximity
- Browsing patterns
- User location
- Operating system
- WiFi network
Deterministic vs. probabilistic tracking
The difference between the two methods lies in the data used to track users.
Deterministic uses known identifiers, enabling you to deliver more accurate personalization at scale and adopt more privacy-friendly practices. Alternatively, probabilistic tracking uses anonymous data points rather than first-party identifiers. So, the precision of probabilistic tracking depends on the volume and quality of anonymous identifiers that comprise the probabilistic model.
Although probabilistic matching is more flexible, it’s not 100% accurate. It makes sense to use it for critical use cases, like in fraud detection, where the datasets are large and complex. But it’s not recommended if your goal is to build data-powered personalized experiences.
Deterministic matching is more accurate simply because no “guesswork” is involved.
Many organizations adopt a hybrid approach that uses deterministic and probabilistic based on the data available and for different use cases.
Benefit from cross-device tracking with Amplitude
In today’s digital world, the need for accurate cross-device tracking will only continue to increase—and Amplitude can help.
With Amplitude CDP, it’s easy to resolve customer identities across touchpoints to build unified customer profiles. As the only customer data platform natively integrated with analytics, Amplitude enables you to track users accurately using a combination of device IDs, user IDs, and Amplitude IDs.
Ready to reap the benefits of cross-device tracking and transform your user experience? Try Amplitude’s self-service demo for free.