These days, it is quite normal for us to use multiple devices for various purposes: the laptop for work, the desktop PC for personal entertainment, the tablet for leisurely online shopping on the sofa, and the smartphone for just about everything – among others. However, many companies fail to leverage this potential, often focusing solely on individual devices or platforms with their advertisements and analytics tools. Consequently, they wear unnecessary blinders – often due to the fear of the technical challenges that such a configuration might involve. Nevertheless, major tools have long provided simple integrations for efficient cross-device and cross-platform tracking.
What is Cross-Device Tracking?
Cross-device tracking aims to break down the limited view of conventional tracking methods and visualize a user journey that spans different devices.
Let’s take a potential customer as an example: On the way home from work, the person sees a display ad on their smartphone and clicks on it. They like the website, so they create an account and subscribe to the newsletter. Two days later, they scroll through the product catalog again – this time on their tablet. Two products end up in the shopping cart, but the purchase is not completed until the evening on the desktop PC.
Without cross-device tracking, these three touchpoints would be recorded as separate users in analytics and ad platforms, as they are only identified via their respective device IDs. In a conventional setup, only the last interaction would be counted as a conversion, leaving the influence of the original display campaign invisible.
Cross-device tracking makes it possible to track the entire user journey across different devices and thus obtain a more realistic picture of the target group’s behavior.
What is Cross-Platform Tracking?
The terms platform and device are often used interchangeably in this context. However, there is a crucial difference, particularly in terms of technical integration: while cross-device tracking refers to different end devices, cross-platform tracking – as the name suggests – focuses on the platform used.
Users can interact with a company through its website and mobile app. Without a consistent connection between these platforms, the user journey is fragmented. Cross-platform tracking ensures that interactions are recorded across all platforms, creating a consistent user experience.
Why is cross-device and cross-platform tracking so important?
As evident from the previous examples, traditional tracking setups that solely record individual devices or platforms lack a comprehensive view of user behavior. This presents several disadvantages:
Personalization and the enhancement of the user experience suffer when decisions are made based on incomplete data that omits important insights. Users often switch between devices and platforms; if these changes are not recorded, gaps in the analysis occur.
Ad performance decreases due to incorrect attribution in campaigns. A conversion may be linked to a duplicate user profile despite being the same individual merely switching devices. Consequently, advertising budgets are spent inefficiently as the actual customer journey remains untraceable.
Moreover, ad targeting is restricted when it focuses solely on individual devices or platforms. Without a cross-device link, users who have previously expressed interest may not be targeted on another device.
Cross-device and cross-platform tracking solve these problems by mapping the end-to-end user journey, enabling more precise analysis, better personalization, and more efficient advertising measures.
Cross-device and cross-platform tracking with Google in 3 steps
Prerequisites
To integrate cross-device and cross-platform tracking with the Google Suite, a login functionality is required for your website and your apps. Google then uses a user ID to recognize users, which remains consistent across all devices and platforms.
Important: This user ID should not be confused with the Google ID. While the Google ID is assigned to a specific device or browser, the user ID creates a link across devices.
The login is used to generate a unique user ID for logged-in users that can be applied across different devices and platforms. However, according to Google’s terms of use, the user ID may not be a personal date. For example, an email address may not be used directly as a user ID. Instead, an anonymized or encrypted ID should be used that does not allow conclusions to be drawn about the user’s identity.
1. receive user ID
In most cases, the user ID is a unique identifier assigned to users in your user database. For it to be used by the Google Tag, it must be available on the website or in the app.
This can be done in various ways on a website:
- Directly via the Google Data Layer
- Via a cookie
- Through an object that can be read via JavaScript
Many website builders, shop systems, or plugins already offer a built-in function for providing this ID. If this is not the case, a brief consultation with the website developer can help find a suitable solution.
2. insert user ID
The user ID must now be transferred to Google. Here are a few important points to note:
- Avoid using a custom dimension for the user ID.
Google offers a special feature to ensure data accuracy. Therefore, the user ID should only be transmitted through the “user_id” parameter and not via any custom dimension that you create. - Do not transfer a user ID if users are not logged in.
If users are not logged in, the user ID parameter should be completely omitted. Custom placeholder values like “Empty” or “NA” should be avoided, as Google may misinterpret them. - Include the user ID with every event
As soon as users log in, the user ID must be transmitted with every event. This ensures consistent identification across devices.
Implementation in Google Tag Manager
In the Google Tag’s configuration settings a parameter called “user_id” is added, which should be filled with the value provided on the website.
Create an event settings variable to ensure that the user ID is sent with every event as long as users are logged in. Then, select it in the respective event settings to reuse it in all relevant event tags.
Implementation in an app
The setUserID function is used for the app integration. As soon as a user ID has been set, it is automatically added to all future events so that manual transfer is no longer necessary.
3. test user ID
Finally, thoroughly test the configuration. The best way to do this is by using the Google Tag Manager preview mode. Both scenarios should be examined:
Logged in users → The user ID should be transferred correctly.
Users who are not logged in → No user ID should be transmitted.
In preview mode, we make sure that the parameters sent and their values appear correctly in the tags.
Testing for app integration
For apps, testing is carried out via the Firebase DebugView. Here too, the user ID should be displayed as soon as users log in.
The configuration has been successfully completed as soon as it is verified that the user ID is only visible to logged-in users for all their events.
