The Death of Third-Party Cookies: What Marketers Are Actually Doing Now

The "cookieless future" has been looming for years. Browser vendors have been phasing out third-party cookies, privacy regulations have tightened consent requirements and marketers have been bracing for impact.

Spoiler alert: we're already in it. Safari and Firefox blocked third-party cookies years ago. Chrome keeps delaying full deprecation but has made it clear the direction is set. And while the headlines make it sound apocalyptic, most marketers have quietly adapted.

The brands that struggled were the ones still relying heavily on retargeting, cross-site tracking and third-party audience data. The ones doing fine? They've already shifted to first-party data strategies, contextual targeting and owned channels.

If you're still figuring out what to do, here's what's working.

What's the Difference Between First-Party and Third-Party Cookies?

Before we talk about solutions, let's clarify what we're losing.

First-party Cookies

These are set by the website you're visiting. When you log into a site, add something to your cart or adjust your preferences, a first-party cookie stores that information so the site remembers you. These cookies only work on that specific domain, they’re not going anywhere.

Third-party Cookies

These are set by a domain other than the one you're visiting. They're placed by ad networks, analytics platforms or other third-party services embedded on the site. Their superpower (and privacy problem) is that they can track you across multiple websites.

💡 Here's why that mattered: if you visited a shoe brand's website and then saw ads for those exact shoes on a news site later, that's third-party cookies at work. The ad network dropped a cookie on the shoe site, recognized you on the news site and served you a retargeting ad.

Third-party cookies enabled cross-site tracking, retargeting, lookalike audiences and a lot of the performance marketing tactics brands got used to. Losing them doesn't break websites, but it does break certain advertising strategies.

What Brands Are Doing Now

The shift away from third-party cookies isn't theoretical anymore. Here's how brands are adapting in practice.

Doubling Down on First-Party Data

The biggest shift is brands treating their own data like gold. First-party data (information collected directly from customers through your website, app, email or CRM) has always been valuable, but now has become essential.

Brands are investing in ways to collect more of it. Email sign-ups, account creation, loyalty programs, surveys, quizzes and gated content all give brands a reason to ask for information in exchange for value. The key is making the exchange feel worth it.

For example: 

• A beauty brand might offer personalized product recommendations in exchange for a quick skin type quiz. 
• A SaaS company might gate a useful template behind an email form.
• An eCommerce brand might offer early access to sales for loyalty members.

The data collected this way is accurate, consented and owned by the brand. It can be used for email marketing, on-site personalization, retargeting (on platforms where you can upload customer lists) and building lookalike audiences.

First-party data also means tighter integration between marketing tools. Brands are connecting their email platforms, CRMs, analytics and customer data platforms (CDPs), so they have a unified view of each customer across touchpoints.

Contextual Targeting Makes a Comeback

Before third-party cookies, contextual targeting was how digital ads worked. Instead of following people around the internet, you placed ads based on the content of the page.

Running an ad for hiking boots? Put it on an outdoor adventure blog. Promoting a project management tool? Advertise on a productivity site.

Contextual targeting fell out of favor because behavioral targeting (based on tracking) felt more precise. But it's making a comeback, and modern versions are way more sophisticated than the old keyword-matching approach.

AI-powered contextual platforms can analyze the sentiment, topic and intent of content in real time. They understand nuance. An article about "best running shoes for beginners" and an article about "why I quit running" are both about running, but the intent is completely different. Modern contextual targeting can tell the difference.

The benefit is that it's privacy-friendly, doesn't require tracking users across sites and still reaches people when they're in the right mindset. It won't replace all the precision of behavioral targeting, but it works.

Retail Media Networks Are Booming

One of the biggest winners in the cookieless shift? Retail media networks.

Amazon, Walmart, Target, Instacart and other retailers have built advertising platforms that let brands run ads directly on their sites and apps. Because these platforms operate within a walled garden (users are logged in, browsing products, and often ready to buy), they don't rely on third-party cookies.

Retail media works on first-party data. The retailer knows what you've searched for, browsed and bought. Brands can target shoppers based on that behavior without needing to track them across the web.

For brands selling through these retailers, it's a no-brainer. You're advertising to people who are already shopping in the category.

For brands not selling on these platforms, it's trickier, but many are experimenting with awareness campaigns anyway because the targeting is so precise.

Retail media is expected to keep growing; it’s one of the few ad channels where targeting actually got better in a cookieless world.

Walled Gardens Tighten Their Grip

Speaking of walled gardens: Facebook, Google, TikTok and other platforms with logged-in users are less affected by the death of third-party cookies because they don't need them.

When you're logged into Facebook, the platform knows who you are. It doesn't need a cookie to follow you across the web (though it does use pixels and tracking for attribution). The same goes for Google's ecosystem, LinkedIn and others.

Brands are leaning more heavily into these platforms because the targeting still works. You can build custom audiences, upload customer lists for retargeting and create lookalike audiences based on first-party data.

The downside? You're more dependent on platforms you don't control. Privacy changes (like Apple's ATT framework limiting Facebook's tracking) and rising ad costs make this strategy expensive. But for now, it's one of the most reliable ways to run performance campaigns.

Server-Side Tracking and Data Clean Rooms

For brands with technical resources, server-side tracking and data clean rooms are emerging as solutions.

Server-side tracking moves data collection from the browser to the server, which gives brands more control and can bypass some browser restrictions. It's not a magic bullet (you still need consent and it doesn't solve cross-site tracking), but it improves data accuracy and reliability.

Data clean rooms let brands and publishers securely share and analyze data without exposing individual user information. For example, a brand could upload its customer list to a clean room provided by a publisher or ad platform, match it against the publisher's audience and run targeted campaigns without either party sharing raw data.

Clean rooms are complex and mostly accessible to larger brands with the resources to use them. But they are becoming more common, especially for collaborations between brands and media companies.

What's Not Working (Or Not Working Yet)

Not every solution is a slam dunk.

Universal IDs (like UID 2.0) are trying to replace third-party cookies by creating a shared identifier based on hashed emails. In theory, this lets the ad ecosystem continue functioning without cookies.

In practice, adoption has been slow, and there are still privacy and consent concerns.

Google's Privacy Sandbox is a set of APIs designed to enable ad targeting and measurement without third-party cookies. It's Chrome-specific, complex to implement and the ad industry has mixed feelings about it. Some see it as a viable path forward. Others see it as Google consolidating control.

The reality is that no single replacement for third-party cookies has emerged. The future is fragmented with different solutions working in different contexts.

What Brands Should Be Doing Right Now

If you haven't already started adapting, here's where to focus.

Audit Your Current Setup

‍Understand where you're relying on third-party cookies. Retargeting campaigns, attribution models and audience targeting are the most affected. Figure out what breaks without them and prioritize alternatives.

Invest in First-party Data Collection

‍Build your email list, encourage account creation and offer value in exchange for information. Make sure your data infrastructure (CRM, CDP, email platform) is connected so you can use what you collect.

Test Contextual Targeting

^‍If you've been running retargeting campaigns, try shifting some budget to contextual placements and see how it performs. You might be surprised.

Explore Retail Media if Relevant

‍If you sell on Amazon, Walmart or other platforms with ad networks, test them. Even small budgets can give you a sense of how they perform.

Get Comfortable with Walled Gardens

‍You're probably already advertising on Facebook, Google or TikTok. Lean into their first-party targeting tools (custom audiences, lookalikes) and optimize for the platforms where your audience is.

Lastly, Don't Panic

‍The sky hasn't fallen. Brands are still running ads, tracking conversions and growing. The tactics have shifted, but the fundamentals haven't.

Find an Agency to Help You Navigate the Cookieless Future

Adapting to a cookieless world is an ongoing shift in how you collect data, target audiences and measure results.

If you're not sure where to start or need help rebuilding your strategy, Breef connects you with vetted performance marketing and analytics agencies who have already helped brands through this transition.

Ready to future-proof your marketing? Book a demo call with Breef and find an agency that gets it. 🤝