Two years ago this July, Google announced it was dropping its plan to deprecate third-party cookies in Chrome. The four-year saga of the “cookieless future” officially ended with a user choice prompt architecture that left cookies technically alive for the vast majority of Chrome users who click through consent screens without reading them.
The reaction at the time ranged from relief to cynicism. The cynical read was that the industry had spent years and billions of dollars preparing for something that never happened — that UID2, RampID, clean room infrastructure, first-party data programs, and contextual targeting reinvestment were all built for a scenario that Google simply withdrew from.
Two years later, the data tells a different story. The companies that built the infrastructure are outperforming those that didn’t. The competitive advantage that was supposed to come from cookie alternative readiness manifested — just through different mechanisms than the cookie deadline created.
What Actually Got Built
The 2020-2024 period of cookieless preparation drove real infrastructure construction. It’s worth cataloging what actually exists today that didn’t exist before the preparation period.
First-party data programs at publishers: The number of publishers with authenticated user bases — email-registered users who have consented to identity-based advertising — grew substantially from 2020 to 2024, driven by the financial case for the authenticated inventory CPM premium. That premium is currently running 40-60% above comparable anonymous inventory. Publishers who built registration and newsletter programs during this period are collecting that premium today, continuously, regardless of Chrome’s cookie status.
Clean room infrastructure: LiveRamp Clean Room, Google Ads Data Hub, Amazon Marketing Cloud, Snowflake-native clean rooms, and clean room specialists like Habu and InfoSum all matured into operational platforms with real enterprise adoption. The clean room market exists at a scale it would not have reached without the forcing function of cookie deprecation preparation. The use cases that clean rooms enable — CRM-to-publisher matching, multi-touch attribution, cross-media reach measurement — are valuable regardless of what cookies do.
UID2 publisher enrollment: The Trade Desk’s UID2 program reached significant publisher enrollment milestones during the preparation period. Those publishers have authenticated identity infrastructure active today that allows them to pass identity signals in bid streams for Safari, Firefox, and opted-out Chrome users — real traffic segments that represent 30-40% of most publishers’ audiences. UID2 doesn’t need cookie deprecation to have a reason to exist.
Advertiser first-party data organization: Brands that used the cookie preparation period as motivation to consolidate their CRM data, implement CDPs, and build structured customer data programs have those assets operational and compounding. The brands that didn’t are still running campaigns against brokered third-party audience segments with increasing regulatory exposure.
The Companies That Built Anyway Won
The most useful analytical frame for the past two years isn’t “was the preparation wasted” — it’s “who built and who didn’t, and how are they performing.”
Publishers with authenticated user programs are consistently outperforming comparable publishers without them on programmatic revenue metrics. The CPM differential is measurable and persistent. The underlying mechanism isn’t cookie deprecation — it’s the pricing premium that identity-resolved impressions command from sophisticated buyers who have first-party data programs to match against.
Advertisers with complete CAPI implementations on Meta are running campaigns with higher signal quality than those still relying on pixel-based attribution. This advantage exists entirely independent of Chrome’s cookie status — it’s a function of server-side event quality versus browser-dependent tracking.
Brands with CDP-organized first-party data are executing CRM re-engagement campaigns, loyalty audience activation, and high-value prospect targeting with fidelity that brands without structured first-party data cannot match. The advantage is measurable in conversion rates and customer lifetime value metrics.
Agencies with clean room operational capability are running publisher-to-advertiser data collaboration for clients that their competitors can’t execute. The capability differential is now a business development differentiator.
In each case, the preparation infrastructure — built specifically to hedge against cookie loss — turned out to generate competitive advantages that don’t depend on the cookie situation at all. The infrastructure solved real problems that existed whether or not Chrome deprecated cookies.
What Didn’t Pan Out
Intellectual honesty requires noting where the preparation investment didn’t deliver what was promised.
Privacy Sandbox API adoption among DSPs and publishers remains limited. The Protected Audience API and Topics API are available in Chrome, but commercial deployment at scale hasn’t materialized because the use cases they were designed to serve — cookieless retargeting and interest-based targeting in Chrome — are unnecessary for the cookie-accepting Chrome majority. The Privacy Sandbox APIs have found limited utility in Safari and Firefox contexts where cookies are already restricted, but the massive investment in Privacy Sandbox integration that was expected to be necessary has largely been deferred.
Contextual targeting reinvestment, which was the investment thesis for a substantial number of adtech startups that raised capital during the 2020-2023 period, has not delivered on the “contextual as cookie replacement” narrative at scale. Contextual targeting is a real and useful advertising signal — but it has not displaced audience-targeted advertising in commercial importance, because the cookie’s actual survival meant advertisers didn’t need to make that substitution.
The vendor consolidation that was predicted — a culling of the identity resolution and cookie alternative space — hasn’t happened as dramatically as anticipated. UID2, RampID, ID5, and multiple other identity frameworks coexist in the market, creating fragmentation that was supposed to resolve when a winner emerged from the post-cookie transition.
The Browser Landscape Has Changed Anyway
Here’s the thing that the “cookies survived” narrative tends to obscure: the browser landscape has changed substantially since 2020, independent of Chrome’s cookie decision.
Safari’s Intelligent Tracking Prevention, active and progressively tightened since 2017, means that third-party cookies have been functionally dead for Apple’s browser user base for years. iOS Safari, macOS Safari, and Firefox together represent approximately 30-35% of browser traffic in North America. For every buyer and publisher, a meaningful portion of their traffic has been operating without third-party cookies throughout the entire preparation period.
Chrome’s user choice prompt architecture, while leaving cookies technically alive for most users, has introduced a bifurcation that is growing. Privacy-motivated users — a disproportionately valuable demographic — are opting out of cookies at rates that matter for targeting programs. The opted-out Chrome segment is not large today, but it is growing as the prompt design becomes more familiar to consumers and as privacy-protective behavior normalizes in the culture.
The mobile advertising ecosystem — app-based advertising through iOS and Android — has been operating without cross-app cookie tracking since Apple’s ATT framework in 2021. Every performance advertising program that relies on mobile app conversions is already in a post-cookie environment.
The “cookies survived” framing is accurate for desktop Chrome specifically. It substantially understates how much of the actual digital advertising ecosystem already operates on cookie-alternative infrastructure.
Where the Advantage Compounds Next
The companies that built first-party data and identity infrastructure during the preparation period have a compounding advantage: the infrastructure improves over time as more data flows through it, more matching history accumulates, and the models built on that data become more accurate.
A publisher that built an authenticated user program in 2022 has four years of behavioral and engagement data on those users. The identity matching accuracy, content recommendation quality, and advertising relevance that those four years of data enable cannot be quickly replicated by a publisher starting now. The head start compounds.
The same dynamic applies to brands with mature CDP deployments — the customer data organization, enrichment, and modeling built over years produces audience understanding that a brand starting today would need years to replicate.
The preparation period created a capability divergence between organizations that invested and those that didn’t. Two years after the deadline disappeared, that divergence is the defining competitive dynamic in data-driven marketing — not the Chrome cookie timeline.
FAQ
Q: With cookies still largely alive in Chrome, is there still a business case for building first-party data programs? Yes, and a stronger one than during the preparation period. The CPM premium on authenticated inventory is documented and persistent. Regulatory pressure on third-party data continues independent of Chrome. CRM-based targeting delivers precision that cookie-based audience segments can’t match for most brands. The business case now stands independently, without needing cookie deprecation as the justification.
Q: What should companies that did not invest in cookieless infrastructure during the preparation period do now? Start with first-party data organization — CDP implementation and customer data consolidation. This is the foundation that clean room activation, identity resolution, and cross-channel measurement all depend on. UID2 publisher integration (for publishers) and CAPI implementation (for advertisers) are high-ROI second steps. Clean room capability follows from first-party data maturity, not the reverse.
Q: Are the clean room vendors that raised capital on the cookieless narrative still viable businesses? The clean room market is healthy, with real enterprise adoption and growing use cases. The specific narrative — “clean rooms as the mechanism for cookie alternative advertising” — was partially wrong, but the genuine use cases (CRM matching, cross-media measurement, audience collaboration) are significant and growing. Habu, InfoSum, and other clean room specialists are generating real revenue from real use cases that don’t depend on cookie deprecation.
Q: Has UID2 reached the scale needed to compete with cookies as a targeting signal? UID2’s open exchange pass rate — the percentage of programmatic bid requests containing a valid UID2 signal — remains below cookie signal density in Chrome. For publishers with strong authenticated user programs, UID2 pass rates on their traffic can be meaningful. As a general open exchange signal, UID2 hasn’t replaced cookies. As a cross-device and authenticated audience targeting signal, it provides capabilities that cookies never provided. The use cases are different; the comparison to cookies as a “replacement” misframes UID2’s actual value.