Zero-Party Data Explained: How it works and why it matters in advertising
This guide is your invitation to an exciting party. One where the guests actually want to be there and tell you exactly what they like.
Welcome to the world of zero-party data.
In this guide, we’ll break down what zero-party data is, how it differs from first-party, second-party, and third-party data (there’s no fourth-party data… yet), and why it’s becoming increasingly important for advertisers navigating a privacy-first, ID-limited ecosystem. We’ll also explore how zero-party data can be used alongside first-party data to crush campaign goals. We’re talking smarter media planning, better personalization, and stronger performance — without sacrificing user trust.
From third-party to zero-party: A quick data countdown
To understand why zero-party data matters so much today, it helps to zoom out and look at the full data spectrum advertisers work with.
Third-party data: The once-mighty triple threat
Third-party data is collected by entities that don’t have a direct relationship with the end user. These data aggregators compile information from multiple sources and stitch it together to create audience segments that advertisers can target at scale.
Historically, third-party data helped marketers to reach new audiences efficiently. But the trade-offs have become harder to ignore:
- Limited transparency into how data was collected
- Growing legal and compliance risk amid changing privacy regulations
- Declining accuracy as cookies disappear and signals degrade
As identifiers become increasingly unreliable and consumers gain more control over their data, third-party data’s role in advertising continues to shrink.
Second-party data: Bridging the gap
Second-party data is essentially someone else’s first-party data, shared through a direct partnership. For example, a retailer might share anonymized purchase insights with a brand partner, or a publisher might make audience data available through a curated data marketplace.
Because it originates as first-party data, second-party data tends to be higher quality than third-party data. Still, it comes with limitations around scale, portability, and dependence on external relationships.
First-party data: The gold standard
First-party data is information a company collects directly from its own audience or customers. This includes things like:
- Website and app behavior
- Purchase history
- CRM and loyalty program data
- Account or subscription information
Because users provide this data through direct interactions, it’s accurate, consented, and highly valuable. In fact, 53% of digital ad professionals say first-party data strategies are their most important focus area for facilitating addressability and measurement.
But even first-party data has limits, especially when it comes to understanding intent and preferences in real time.
Zero-party data: The unsung hero
Zero-party data goes one step further.
Zero-party data is information that users intentionally and proactively share with a brand. Think preferences, needs, interests, or purchase intent — explicitly stated rather than inferred. For the visual learners, check out our colleagues’ video explaining zero-party data in Central Park.
Common zero-party data sources include:
- Surveys and polls
- Quizzes and product finders
- Preference centers
- Interactive content and forms
Unlike first-party data, which is observed through behavior, zero-party data is declared. The users tell you exactly what they want, and often why.
That clarity is what makes zero-party data especially powerful in advertising today.
Overview: Zero-, first-, second-, and third-party data
| Zero-party data | First-party data | Second-party data | Third-party data | |
|---|---|---|---|---|
| Definition | Data users intentionally and proactively share with a brand | Data collected directly from owned channels based on user interactions | Another company’s first-party data shared via direct partnership | Data collected by entities with no direct user relationship |
| Who collects it | The brand, with explicit user input | The brand | A trusted partner of the brand (publisher, retailer, platform) | Data aggregators or brokers |
| Examples | Surveys, quizzes, preference centers | Website/app behavior, CRM data, purchases, loyalty programs | Publisher audience segments, retailer purchase data | Cookie-based segments, inferred demographics |
| Consent | Explicit and intentional | Implicit but consented | Depends on partner’s consent framework | Often opaque to users |
| Data accuracy | Very high (self-declared) | High (observed behavior) | High (originally first-party) | Variable |
| Privacy risk | Very low | Low | Medium | High |
| Key strengths | Trust-building, highly precise, privacy-forward | Reliable, durable, strong measurement | Quality data beyond owned audiences | Broad reach |
| Key limitations | Potentially short shelf life, requires strong UX | Limited to owned audiences | Partner-dependent, limited portability | Regulatory risk |
| Use cases | Personalization, messaging, preference-based targeting | Retargeting, lifecycle marketing, attribution | Audience expansion, co-marketing | Legacy prospecting, reach extension |
Why zero-party data matters in advertising
As identity signals disappear and expectations around privacy arise, zero-party data offers a rare combination: precision, consent, and trust.
1. Better user experience
Zero-party data gives advertisers direct insight into user preferences, making it easier to deliver relevant messages without guesswork. When users feel understood, engagement and conversion rates tend to follow.
According to our recent survey on data privacy, 72% of users are less likely to pay to remove ads if those ads are targeted and interesting. And 48% said relevant ads are the most appealing and most likely to drive engagement.
When users tell you what they want, personalization stops feeling creepy and starts feeling helpful.
2. Trust, transparency, and control
Zero-party data is built on a clear value exchange. A user shares information because they expect something in return — better recommendations, tailored content, or a more relevant product experience.
For example, a beauty brand might use a quiz to recommend a custom skincare routine. As long as it’s clear how that information will be used (and how it won’t), the interaction builds trust instead of eroding it.
In a time when consumers are more aware (and skeptical) about data usage, that transparency matters.
3. Privacy-forward by design
Because zero-party data is voluntarily shared, it aligns naturally with privacy regulations like GDPR and CCPA. There’s less ambiguity around consent, purpose limitation, and lawful use compared to third-party data.
For advertisers and agencies, that means lower compliance risk and more confidence in how data is activated across channels.
4. Less dependence on third-party signals
As third-party cookies fade and mobile identifiers become harder to access, advertisers need durable alternatives. Zero-party data doesn’t rely on cookies or device IDs. It relies on direct relationships.
That makes it a more future-proof input for targeting, personalization, and measurement strategies.
Using zero-party data in media planning
Zero-party data works best when it complements, not replaces, first-party data.
For media planners and buyers, the opportunity lies in helping brands design experiences that encourage users to share information willingly. That might include:
- Interactive quizzes or assessments
- Preference centers tied to content or commerce
- Gated experiences that unlock value in exchange for insight
When activated thoughtfully, zero-party data can inform audience segmentation, creative messaging, contextual targeting, and even supply selection. All while respecting user privacy.
The key is making the value exchange obvious and worthwhile.
Considerations before RSVPing to the zero-party
With great data comes great responsibility.
While consumers understand that brands use data to personalize experiences, comfort levels are shifting. Recent data shows that most consumers respond positively to ad personalization, yet they are wary about the data that powers it.
A few best practices:
- Be radically transparent. Clearly explain what data is collected and how it’s used.
- Avoid complacency. Zero-party data can age quickly. Preferences change, and one-time inputs may lose relevance.
- Keep it useful. Only ask for information you can actually act on — and act on it well.
Zero-party data isn’t a shortcut. It’s a relationship.
Final thoughts
Data, privacy, and identity remain at the center of modern advertising. And zero-party data is becoming one of the most valuable tools in that mix. Not because it’s new, but because it’s intentional.
When users choose to share information, and brands use it responsibly, everybody wins.
Frequently asked questions
Zero-party data in marketing is information that users intentionally and proactively share with a brand, such as preferences, interests, purchase intent, or product needs. Unlike behavioral data that’s observed, zero-party data is explicitly declared by users through surveys, quizzes, preference centers, or interactive content. This makes it highly accurate and privacy-compliant, as users voluntarily provide information in exchange for personalized experiences, better recommendations, or tailored content.
First-party data in marketing is information a company collects directly from its own audience through owned channels and customer interactions. This includes website and app behavior, purchase history, CRM data, loyalty program activity, and subscription information. Because it comes from direct relationships with users, first-party data is accurate, consented, and highly valuable for personalization, retargeting, and measurement. It’s considered the gold standard for privacy-compliant audience insights.
The key difference between zero-party and first-party data is how it’s obtained. Zero-party data is explicitly declared. Users intentionally tell you what they want through surveys, quizzes, or preference centers. First-party data is observed. You collect it by tracking user behavior on your website, app, or through purchases. Both are collected directly from your audience, but zero-party data provides stated preferences while first-party data reveals behavioral patterns. Used together, they create a complete picture of user intent and action.
Zero-party data is collected through interactive experiences where users voluntarily share information:
- Surveys and polls asking about preferences or interests
- Quizzes and product finders that recommend personalized solutions
- Preference centers where users control communication and content settings
- Interactive forms and assessments tied to gated content or exclusive offers
- Account setup flows that capture customization choices
The key is making the value exchange clear. Users should understand what they’ll get in return for sharing information, whether that’s better recommendations, tailored content, discounts, or a more relevant product experience.
Yes, zero-party data is highly effective for targeted advertising because it provides explicit user preferences and intent. Advertisers can use zero-party data to:
- Create precise audience segments based on stated interests rather than inferred behavior
- Personalize ad creative and messaging to match declared preferences
- Inform contextual targeting strategies without relying on cookies or device IDs
- Improve relevance across channels including display, social, CTV, and email
- Power preference-based retargeting that respects user choices
Because users voluntarily share this information expecting a better experience, zero-party data enables personalization that feels helpful rather than invasive. When combined with first-party behavioral data, it creates powerful targeting strategies that balance effectiveness with user trust. And that’s essential in today’s privacy-first advertising landscape.
Zero-party data naturally aligns with privacy regulations like GDPR, CCPA, and other consent-based frameworks because it’s voluntarily shared by users with clear intent. When users explicitly provide information through surveys, quizzes, or preference centers, they understand what data is being collected and why — meeting consent and transparency requirements. Unlike third-party data with ambiguous origins, zero-party data has clear purpose limitation and lawful basis for processing. This reduces compliance risk and makes it easier to honor user rights like data access, correction, and deletion. The key is maintaining transparent policies about how zero-party data will be used and ensuring users can update or withdraw their preferences at any time.