Breadcrumb tracking for cross-session and cross-device user identification | Leopose Digital

Leonardo Pose, the founder of Leopose Digital and Stape's partner, has developed a tracking method called the “Breadcrumb tracking method.” This approach enables the logging of user activities across multiple sessions and devices. In this article, we will look in-depth at how this method works and its benefits.

Leonardo Pose needed to track user behavior across multiple sessions and devices and attribute the events to a specific website visitor. However, he faced challenges due to browser restrictions - particularly Safari's Intelligent Tracking Prevention (ITP) - which limited cookie lifespans and disrupted tracking capabilities.

To address the problem with the lifespan of cookies, Leonardo has decided to create a custom domain using the same origin, which allows first-party cookies to be set up. Also, he opted for Stape’s Cookie Keeper. The power-up allowed prolonging cookies' lifetime and guaranteeing that marketing cookies continue to work even if the original cookies were erased. 

As the key identifier to track users’ behaviour, Leonardo has chosen User ID. He used Stape’s User ID power-up, which allowed this parameter to be added to the server GTM event data.

In the case of Leopose Digital, after the person has provided the data (name, email, and phone number) by purchasing the course on the “Breadcrumb tracking method”, this data was saved and recorded in a BigQuery table. The unique user ID was assigned to each user who consented to data processing and/or bought a course. It is then integrated into their corresponding record within the BigQuery table.

Besides email, phone, name, and assigned User ID, Leonardo also records the browser and device type, city, country, and region of the website visitor. He uses another power-up to track this data list: GEO Headers.

Here is how it looked on the side of the server GTM - configured Request Header variables. You can find the detailed instructions on this Request Header variable configuration in our article.

The data on the user (including the User ID) is saved in cookies. If the person visits the website later, Leonardo could easily identify the user and create a log of users’ actions before a significant event happened (e.g., purchasing a course on “Breadcrumb tracking method”).

All the user data that website visitors gave consent to process, as well as event data, is stored in a BigQuery table. Leonardo uses the “Write to BigQuery” tag to send data to BigQuery. From BigQuery, the data can be sent to various tools, for example, Google Analytics 4 or Looker Studio for visualization and easier segmentation. In the screenshot below, you can see the example in Looker Studio kindly provided by Leonardo. 

Before users entered their email address, events under the same user_id couldn’t be identified. Leonardo Pose’s solution changed that; after users gave their email via consent mode, all past events from that user_id became identifiable.

Later, Leonardo decided to share the method with others. He developed the “Breadcrumb method” and teaches how to implement it.

Leonardo Pose’s "Breadcrumb tracking method" has proven to be an effective solution for cross-session user attribution. By creating a persistent User ID and using Stape’s power-ups like Cookie Keeper, User ID, and GEO Headers, the method reduced the impact of browser restrictions and unified the customer journey. As a result, all past events under a single user ID became identifiable after a user gave consent.