Jan 20, 2025
Third-party cookies: what’s fact and what’s fiction?
6-MINUTE READ | By Milja Nevalainen
[ Updated Jan 20, 2025 ]
Third-party cookies have been a hot topic for years, and their future remains a source of confusion and debate, with many questions, such as:
- What exactly are third-party cookies, and why are they so controversial?
- Are third-party cookies really disappearing, or is there more to the story?
- How will their decline impact tracking and personalization?
- What steps can I take now to future-proof my digital marketing strategies?
Despite their significant tracking benefits, the future of third-party cookies is still uncertain. Privacy concerns and regulations make them an unstable foundation for building a business.
In this article, we’ll explore why third-party cookies are controversial and distinguish between fact and fiction. This will help you understand how to adapt your strategies for a privacy-centric world. Let’s dive in.
What are third-party cookies?
Third-party cookies are small data files created by domains other than the one you’re currently visiting. These cookies are primarily used to track users across different websites, enabling retargeting, personalized ads, and cross-site behavioral data analysis.
How are third-party cookies used for advertising?
Imagine you visit ShopA.com to browse for a winter jacket. ShopA.com has a script in its website code linked to AdNetworkX. This script drops a third-party cookie from the ad network into your browser, capturing your interest in winter jackets.
Later, when you visit an unrelated website that’s selling ad space to advertisers using AdNetworkX, their script taps into that same cookie in your browser. The cookie reveals your interest in winter jackets, and the ad network uses this information to serve you personalized ads on the new website.
If you click one of these ads and make a purchase, the ad network records this action. It then ties it to the browsing data already collected through that third-party cookie, creating a comprehensive profile of your behavior.
As you can see from this example, tracking users across different websites, retargeting, and marketing attribution would be extremely challenging without third-party cookies.
What’s zero, first, second, and third-party data?
Here’s how third-party cookies differ from other types:
- Zero-party data is data that comes directly from your audiences. Think survey responses, form fills, product and preferences quizzes, etc.
- First-party data includes information like purchase history, browsing behavior, and customer profiles. Similar to zero-party data, his first-party data is the most valuable and reliable as it comes directly from your audience.
- Second-party data is data that you acquire from another company. For example, if you partner with another business and they share their customer data with you, like a retailer sharing customer data with a complementary brand.
- Third-party cookies are data collected by entities that don't directly relate to the consumer. They are aggregated from various sources and sold to advertisers and marketers. Third-party data tends to be less accurate and reliable than first- or second-party data.
How can you make the most of each data type?
Here are some quick tips to use each data type effectively:
- Build a collection of zero and first-party data as it provides the most direct insights into your customers. Use it to personalize experiences, improve products/services, and inform marketing strategies.
- Seek out second-party data partnerships to expand the understanding of your audience beyond your customer base. This can help you reach new potential customers.
- Use third-party data cautiously and supplement your first and second-party data. While it can provide broader market trends and competitive intelligence, it shouldn't be the only basis for important decisions.
- The key is to build a data strategy that balances these different data sources to gain the most accurate customer insights. Too much emphasis on third-party data can lead to less effective targeting and personalization.
For a deeper dive into gathering and using reliable data, check out our guide on marketing data integration.
Why are there privacy concerns surrounding third-party cookies?
Third-party cookies play a crucial role in personalized marketing—helping advertisers tailor messages, improve user experience, and deliver relevant ads. However, these same cookies also raise legitimate privacy questions:
- Tracking across multiple websites: People may worry about privacy because third-party cookies track behavior across multiple websites without direct approval. Many people don’t realize how much of their browsing is being monitored. This leads to concerns about data being collected and sold without their knowledge.
- Transparency and control: Lack of transparency adds to the confusion. Users often don’t know which companies collect their data or how it’s used. This tension raises a moral question: Is more personalization worth what feels like digital surveillance?
- Regulatory changes: Regulations like the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) have put increased scrutiny on third-party cookies and data collection practices.
- Industry innovation: As third-party cookies become more prominent, marketers and tech providers are exploring alternate solutions, such as Conversion API, cohort-based targeting, and enhanced user consent tools. These approaches aim to balance personalization with user privacy, though the market is still determining which methods will succeed.
- Varied perspectives and shifting timelines: Some marketers see third-party cookies as vital for targeted advertising, while others view them as a breach of user trust. Different browsers have adopted unique strategies—some delaying their plans to eliminate cookies, adding t uncertainty about when (and how) the transition will be finalized.
In short, third-party cookies offer clear benefits for personalized marketing but also spark concerns about transparency and data rights. As technology and regulations evolve, the industry is experimenting with ways to deliver relevant ads while respecting user privacy—ultimately aiming for a healthier balance between personalization and control.
Which browsers are phasing out third-party cookies?
Let's examine how major web browsers handle cookie privacy policies and their ongoing changes. Here are the latest updates:
- Safari uses “Prevent Cross-Site Tracking” to limit third-party cookies and stop them from building detailed user profiles. Learn more in Safari’s Privacy Guide.
- Firefox blocks third-party cookies by default with its “Enhanced Tracking Protection” feature. However, they announced that by 2025, they plan to remove the Do Not Track toggle from its Privacy and Security settings, claiming it was because “nobody was listening anyway.”
- Google Chrome initially planned to phase out third-party cookies by 2022. However, it delayed the move until 2024 and then again until 2025.
More recently, Google abandoned its earlier plans to phase out third-party tracking cookies in its Chrome browser. This change was introduced as part of the Privacy Sandbox initiative, a set of controversial proposals to improve user privacy. Learn more details about Google U-turn on 3rd-party cookies.
These changes highlight why exploring cookieless tracking and first-party data is essential. Before we discuss preparing for a cookieless future, let’s see how third-party cookies affect you.
How can the lack of third-party cookies impact you?
Third-party cookies made it easier for you to:
- Retarget users: Bring back visitors who showed interest in your site.
- Measure ad performance: Identify which campaigns work well and where to improve.
- Analyze behavior: Understand user actions so you can create more relevant offers.
But if these cookies disappear or become more restricted, you’ll lose tools that support personalization and measurement. Relying on them also brings added challenges when building brands, campaigns, and solutions:
- Audience identification: Without third-party cookies, finding the right groups of people is more challenging. You may need to rely on logins, email signups, or cohort-based targeting.
- Personalization: You used cookies to tailor recommendations and offers. Now, you’ll depend on your data and contextual information to understand user preferences.
- Measurement and attribution: Without cross-site tracking, it’s more challenging to determine which channels drive results. This is where media mix modeling (MMM) comes in. Initially developed in the 1950s for traditional media like TV, radio, and print, MMM is now gaining traction for online channels as well. As third-party cookies decline, MMM offers a way to measure and optimize your entire marketing mix—both offline and online—without relying on individual user-level tracking.
- Integrations and compatibility: Many tools rely on third-party cookies. Embracing cookie-free technologies means adjusting your workflows and data flows.
- Reaching more people efficiently: Third-party cookies once helped you find broad audiences. Today, you can use cohort-based approaches, contextual ads, and first-party strategies to connect with customers meaningfully.
As you adjust, remember that change brings new opportunities. By exploring alternatives now, you can strengthen your privacy-focused approach to reaching and understanding your audience.
How to prepare for a cookieless future
To succeed, start adjusting now. Here are some cookieless tracking solutions in the market:
- Have a strategy for collecting and using zero and first-party data effectively.
- Consider contextual advertising, where you match ads to the surrounding content instead of user profiles.
- You can also try cookieless tracking methods, such as server-side data collection, which shifts tracking from the user’s browser to your servers.
- Privacy-preserving tools like Google’s Topics API let you reach audiences without identifying them individually.
- Finally, consider second-party data partnerships—collaborating with trusted partners to share data directly and responsibly without relying on third-party cookies.
Our comprehensive guide helps you learn more about adjusting your strategies for ending third-party cookies.
Third-party cookies are not the future; adaptation is essential.
Third-party cookies aren’t your long-term solution. Instead, focus on building trust, using first-party data, and exploring privacy-friendly tracking options.
Preparing for a cookieless future involves experimenting with new tools and methods that protect user privacy while keeping your campaigns effective.
Plan for a future without third-party cookies
Explore practical ways to track your marketing performance in a privacy-centric landscape. Our guide to cookieless tracking covers everything from emerging technologies to strategic best practices—so you can stay ahead without relying on third-party cookies.
About the author
Milja Nevalainen
Milja is a Data Analytics Consultant at Supermetrics. With her in-depth knowledge of marketing analytics and dashboarding, she’s helping Supermetrics clients build impactful dashboards in Looker Studio and Power BI. Besides, she hosts multiple training sessions and webinars to help our audience learn how to use data to improve their performance. Before Supermetrics, Milja honed her skills in the biggest agencies, for example, GroupM Finland and OMD, where she was involved in strategic media planning and competitive analysis.
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