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What is Cross Site Tracking? Everything You Need To Know

Paul Jarvis · Apr 22, 2024

Have you ever felt like the internet knows a little too much about you? Perhaps you've browsed for a product on one website, only to see ads for it follow you around the web?

Welcome to the world of cross-site tracking.

Cross-site tracking has numerous applications and affects your online experiences, as well as those of your website visitors. But how does it work exactly? In this guide, we will explore what cross-site tracking entails and what you can do about it.

What is Cross Site Tracking?

Cross-site tracking is the practice of monitoring and recording users' online activities as they navigate across different websites and online platforms.

The primary objective of cross-site tracking is to collect data about users' browsing behavior, interests, and preferences, which can then be used for purposes such as targeted advertising, analytics, website optimization, and personalization.

While cross-site tracking can offer benefits in terms of improving user experiences and enabling personalized content, it also raises significant concerns regarding user privacy, data security, and consent.

Understanding Cross Site Tracking

Although cross-website tracking might seem a bit complicated at first glance, we have a quick bullet-point list for you that succinctly illustrates how the process works:

  1. Cross-site tracking relies on cookies (or similar), which are small data files stored on users' browsers.
  2. Websites use first-party cookies to remember user preferences and settings.
  3. Third-party cookies, set by domains other than the visited site, extend tracking across multiple websites.
  4. Advertising networks and analytics firms utilize third-party cookies to track users' activities.
  5. Session replay scripts record and analyze user behavior on websites.

These techniques enable cross-site tracking for personalized experiences and targeted advertising.

Is Cross-Site Tracking Legal?

Cross-site tracking itself is not inherently illegal under the GDPR but it is subject to strict requirements and limitations. The issue lies in how the data is collected and used.

The GDPR emphasizes user privacy and control over their data. This means that cross-site tracking can only be GDPR-compliant if certain conditions are met:

  1. Consent: Users must give their explicit consent for their data to be tracked across websites. This consent needs to be freely given, specific, informed, and unambiguous. Basically, users need to clearly understand what they're agreeing to.
  2. Transparency: Websites must be transparent about what data is being collected, how it's used, and with whom it's shared. This information should be easily accessible through a privacy policy.
  3. Data minimization: Websites should only collect and process personal data that is necessary for the specific purpose of tracking. Excessive data collection is not allowed.
  4. Right to object: Users have the right to object to the processing of their personal data for marketing purposes, including cross-site tracking.
  5. Security: Websites must implement appropriate technical and organizational measures to ensure the security of the personal data collected through tracking.

So, if you are a website owner and use cross-web tracking, it's essential to ensure compliance with regulations. First, make sure you have a cookie policy and privacy policy banner in place. These let your users know that you're using trackers and provide details on their purpose and any third parties involved - it's all about transparency.

Second, don't activate those trackers until you've got the green light from your users. Consent is crucial here, and it needs to be obtained before any tracking begins, although there might be some exceptions depending on your website's functionalities.

How is Cross-Site Tracking Technology Used?

Many types of entities or organizations engage in ongoing cross-site tracking efforts to enhance the quality of their data. Among the most popular uses of cross-website tracking are the following:

  1. Online Advertising: Cross-site tracking is extensively used in online advertising to deliver targeted ads to users based on their browsing history, interests, and demographics. This data is then used to create user profiles and serve personalized advertisements that are more likely to be relevant and engaging to individual users.
  2. Analytics and Website Optimization: Website owners and marketers use cross-site tracking techniques to gather data about user interactions and behavior on their websites. This data helps them analyze user engagement, identify popular content, track conversion rates, and optimize the user experience.
  3. Personalization and Recommendation Systems: Cross-site tracking is also used to power personalization and recommendation systems on websites and online platforms. By tracking users' browsing and purchase history across different sites, these systems can suggest relevant products, content, or services tailored to each user's interests and preferences.

Different Types of Cross-Site Tracking Methods

There are many methods to conduct cross-web tracking strategies, with the most popular four common practices being the following.

1. First-party cookies

These are cookies set by the website a user is currently visiting. First-party cookies are primarily used for basic website functionality, such as remembering login information or items in a shopping cart. However, they can also be used to conduct the activity of tracking user behavior on the website.

2. Third-party cookies

These are cookies set by domains other than the one the user is currently visiting. Third-party cookies are commonly used by advertising networks and analytics companies to track users across multiple websites. They can be embedded in advertisements or included in website elements such as social media buttons.

3. Tracking pixels

Also known as web beacons or pixel tags, tracking pixels are tiny, invisible images embedded into web pages or emails. When a user loads a web page or opens an email containing a tracking pixel, it sends information back to the server, allowing the sender to track the user's activity, such as whether an email was opened or a web page was visited.

4. Fingerprinting

Digital fingerprinting involves collecting various pieces of information about a user's device and browser configuration to create a unique identifier, or "fingerprint."

This fingerprint can then be used to track the user across different websites, even if cookies are disabled. Information used for fingerprinting may include browser type, operating system, screen resolution, installed fonts, and plugins.

Future of Cross-Website Tracking

Understanding how cross-website tracking works is important for everyone, but it's also crucial to prioritize transparency, consent, and privacy-focused practices.

Popular web analytics tools such as Google Analytics 4 are legally risky to use even with a consent notice, and the data they collect might be later sold to advertising companies or data brokers.

As Google is ending support for third-party cookies in 2024, it's essential to explore better ways to provide our visitors with the personalized experiences they deserve without compromising their privacy.

At Fathom Analytics, we don't use cookies or similar technologies. Instead, we have pioneered collecting analytics data without invading anyone's privacy or personal information.

By embracing privacy-focused analytics solutions like Fathom, website owners can navigate the changing landscape of web analytics while respecting their visitors' right to privacy.

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Paul Jarvis

Paul Jarvis, author + designer

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