Third-Party Cookies Are Dying. Here's What Comes Next for Intent Data.
With third-party cookies on the way out, marketers need new sources of buyer intent. Zero-party data and deterministic signals are filling the gap.
The Cookie Apocalypse Is Here
For over two decades, third-party cookies were the backbone of digital advertising and intent data collection. They powered retargeting, audience segmentation, and cross-site behavioral tracking.
That era is ending. Safari and Firefox blocked third-party cookies years ago. Chrome — representing over 60% of browser market share — has been phasing them out progressively. And privacy regulations worldwide are making cookie-based tracking increasingly untenable even where technically possible.
For marketers and data buyers, the question isn't whether to adapt. It's how.
What We're Losing
Third-party cookies enabled three core capabilities:
1. Cross-site tracking: Following a user's browsing behavior across multiple websites to build interest profiles 2. Retargeting: Showing ads to users who visited your site but didn't convert 3. Audience segmentation: Grouping users by behavior patterns for targeted campaigns
These capabilities powered a massive ecosystem of data management platforms (DMPs), demand-side platforms (DSPs), and data brokers who aggregated cookie-based behavioral signals into intent data products.
Why Cookie Alternatives Fall Short
Several technical alternatives have been proposed — and most have significant limitations:
Google's Privacy Sandbox
Google's Topics API groups users into broad interest categories based on browsing history, processed on-device. It's more private than cookies, but the signal is coarse. You know someone is interested in "Business Software" — but not that they're evaluating CRM platforms with a Q2 timeline.
Universal IDs
Solutions like Unified ID 2.0 and LiveRamp's RampID create persistent cross-site identifiers based on hashed email addresses. They require user consent and publisher adoption, which limits scale. They also face ongoing regulatory scrutiny.
Contextual Targeting
Contextual advertising — matching ads to page content rather than user behavior — is privacy-friendly but provides no individual-level intent signal. You know someone is reading an article about solar panels, but you don't know if they're a homeowner in a solar-friendly state with a south-facing roof.
The Rise of Deterministic Intent Signals
The real opportunity isn't in replacing cookies with a technically similar mechanism. It's in shifting to fundamentally different — and often better — data sources.
Zero-Party Data (ZPD)
Zero-party data is information that consumers intentionally and proactively share. It includes:
- Survey responses ("I'm interested in solar panels for my home")
- Quiz completions ("Find the right mortgage rate for you")
- Preference declarations ("I want to receive offers for electric vehicles")
- Account registrations with declared interests
- Building permits: A homeowner pulling a permit for electrical work is a strong signal for solar, HVAC, or home renovation services
- Business registrations: A new LLC filing in a specific industry indicates a business that needs software, insurance, and professional services
- Property transactions: A recent home purchase signals demand for moving services, furniture, insurance, and home improvement
- Patent filings: Companies filing patents in specific technology areas reveal R&D investment direction
- Technology stack detection: Scanning websites and job postings to identify what tools a company uses — and when they change
- Job posting analysis: A company hiring a "Salesforce Administrator" is a strong signal for Salesforce ecosystem vendors
- Funding and M&A events: New funding rounds create buying signals across multiple categories
- Topic surge detection: Monitoring content consumption across business publications at the company level (via IP resolution, not individual cookies)
- Zero-party data partnerships for declared intent
- Public records monitoring for life event and business signals
- Technographic scanning for B2B technology signals
- First-party data from your own website and product interactions
- Progressive profiling on your website
- Product usage analytics for expansion signals
- Customer survey programs for satisfaction and intent data
- Event and webinar attendance tracking
- What was the original data source?
- What consent was obtained (if applicable)?
- When was this signal captured?
- How was it enriched or processed?
ZPD is the highest-quality intent signal available because it represents explicit, declared intent. No inference, no probabilistic modeling — the consumer told you what they want.
The challenge with ZPD is scale. Unlike cookies, which passively collected data from billions of users, ZPD requires active consumer participation. Building a ZPD supply network requires partnerships with publishers, apps, and platforms that collect this data with consent.
Public Record Signals
Some of the strongest intent signals come from public records that have nothing to do with web browsing:
These signals are deterministic (not probabilistic), publicly available, and don't require any tracking technology.
Technographic and Firmographic Signals
For B2B intent, cookie deprecation matters less because the strongest signals were never cookie-dependent:
Building a Post-Cookie Intent Strategy
1. Diversify Your Signal Sources
Don't replace cookies with a single alternative. Build a portfolio of intent signals from multiple sources:
2. Invest in First-Party Data Infrastructure
Your own customer data is your most valuable asset. Build systems to capture, enrich, and activate first-party signals:
3. Prioritize Signal Quality Over Quantity
Cookie-based intent data was high-volume but low-quality. A single page visit generated a signal, but most page visits don't indicate real buying intent.
Post-cookie signals tend to be lower-volume but higher-quality. A building permit or a declared preference is worth hundreds of anonymous page views. Optimize for conversion rate, not lead volume.
4. Demand Provenance and Compliance Documentation
As data sources shift from passive tracking to active collection and public records, provenance becomes critical. For every intent signal you purchase, you should be able to answer:
The Bottom Line
The death of third-party cookies isn't a crisis — it's a correction. Cookie-based intent data was always a blunt instrument: probabilistic, privacy-invasive, and increasingly inaccurate.
The alternatives — zero-party data, public records, technographic signals, and first-party data — are more accurate, more compliant, and more predictive of actual buying behavior.
At SIE Data, we never relied on third-party cookies. Our intent signals come from zero-party data partnerships, public record monitoring, technographic scanning, and consented behavioral data. Every signal carries provenance metadata and passes through our compliance pipeline.
The post-cookie future isn't something we're preparing for. It's how we've always operated.
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Future-proof your revenue
As cookies deprecate, zero-party data becomes more valuable. SIE Data pays publishers 8-30% revenue share — no cookies, no tracking pixels.