Third-party cookies are fading out, privacy rules are getting stricter, and ad platforms are harder to trust blindly. In this new reality, the data that actually matters is the data you own.
That is where first-party and zero-party data come in.
Both come directly from your customers, but they are not the same. One is based on what people do. The other is based on what they tell you. When you understand the difference and use both together, you get more accurate tracking, better personalization, and stronger ROI.
Let’s break it down.
What Is First-Party Data?
First-party data is information you collect from people as they interact with your own properties and channels.
Examples include:
- Website and app analytics such as pages viewed and time on site
- Add to cart, checkout, and purchase events
- Email engagement such as opens and clicks
- CRM and support data including tickets and chats
This data is usually collected in the background through tools like Google Analytics 4, your eCommerce platform, and your CRM. If your first-party tracking is not capturing accurate events, exploring server-side tagging can help you understand how to strengthen the stability of these signals.
Key traits of first-party data:
- You control it because it is collected on your domain
- It is relevant because it is based on real customer behavior
- It is privacy-friendly when implemented correctly
The limitation is that first-party data tells you what someone did, but not always why they did it.
What Is Zero-Party Data?
Zero-party data is information a customer intentionally and proactively shares with you.
Examples include:
- A preference quiz such as “Tell us your goals or style”
- A profile or preference center
- Survey answers
- Form fields that go beyond the basics
Instead of you interpreting behavior, the customer is directly telling you their preferences.
Key traits of zero-party data:
- It is explicit because the user knows they are sharing it
- It is accurate since it comes directly from the customer
- It shows high intent because customers share it to receive better value
Zero-party data is smaller in volume but much richer in insight.
Zero-Party vs First-Party Data: Key Differences
Here is an easy comparison:
How it is collected
- First-party data: collected from behavior such as views, clicks, and purchases
- Zero-party data: provided directly through surveys, quizzes, and preference forms
Customer awareness
- First-party data: collected during normal browsing
- Zero-party data: shared intentionally by the customer
Understanding level
- First-party data: shows actions
- Zero-party data: shows preferences and intentions
Volume
- First-party data: large dataset
- Zero-party data: smaller but more precise
Both are privacy-friendly and more reliable than third-party data. Many brands also re-evaluate how their tracking operates by comparing server-side vs client-side tracking to understand which method offers better long-term accuracy.
Why Marketers Need Both
Using only first-party data leaves gaps because you rely on assumptions.
Using only zero-party data also leaves gaps because not everyone answers questions or fills forms.
When you combine them:
- You get clear insight into what people want and what they actually do
- You personalize content and recommendations more accurately
- You reduce irrelevant targeting and wasted ad spend
- You build trust through transparent data collection
For eCommerce brands, this results in:
- Higher engagement
- Higher conversion rates
- Better audience quality for ads
- Stronger customer loyalty
How to Collect Zero-Party Data and Combine It With First-Party Data
You do not need complex tools to start collecting zero-party data. You only need simple touchpoints where customers share information.
Here are effective methods:
Post-purchase surveys
Ask what made them buy, what they were searching for, or what could improve their experience.
Product finder or recommendation quizzes
These are highly engaging and reveal personal preferences.
Email or account preference centers
Let people choose topics, email frequency, and product interests.
On-site polls or micro-questions
Simple questions like “What are you shopping for today?” provide valuable insight.
Once you collect zero-party data, combine it with first-party data:
- Use GA4 and accurate event tracking to capture views, add to cart, begin checkout, and purchases. If your GA4 numbers do not match expectations, reviewing GA4 problems can help you fix tracking gaps before layering zero-party insights on top.
- Create segments based on behavior
- Match behavior with stated preferences to send better recommendations
- Trigger personalized emails or offers when both data types align
This is the foundation of modern personalization and smarter marketing.
How Conversios Helps You Use Both Data Types
To get real value from zero-party and first-party data, your tracking must be accurate and complete. That is where Conversios helps.
Conversios allows Shopify and WooCommerce stores to:
- Set up accurate first-party tracking through Google Analytics 4
- Use server-side tracking to improve event accuracy and help platforms receive more consistent signals. Understanding the benefits of server-side tracking can help you decide whether this approach is right for your store.
- Sync clean purchase events to Google, Meta, TikTok, and Microsoft
- Ensure your ad platforms receive the data needed for optimization
Once your tracking foundation is strong, you can confidently gather zero-party data through quizzes or surveys and know that real customer actions are being tracked correctly.
This gives you a clear view of your customer journey and reduces the common issues of missing or mismatched data.
Final Thoughts
Zero-party and first-party data work best together.
- First-party data shows what customers did
- Zero-party data shows what customers want
In a privacy-first world, brands that combine both will deliver better experiences, stronger personalization, and far more accurate marketing results.
Start by improving your first-party tracking. Then add simple, helpful touchpoints where customers can share more about themselves.
Conversios helps you build a reliable tracking setup so you can confidently use both data types to grow your business.
Frequently Asked Questions
Q. What is the difference between zero-party and first-party data?
Zero-party data is information customers intentionally share with you, such as preferences or goals. First-party data is collected from customer actions on your website or app, such as product views or purchases.
Q. Why is zero-party data important for eCommerce brands?
Zero-party data gives clear insight into what customers want, which helps brands personalize product recommendations, emails, and offers with higher accuracy.
Q. How can brands collect zero-party data without hurting conversion rates?
Brands can collect zero-party data using short quizzes, post-purchase surveys, preference centers, polls, and micro-questions placed at natural touchpoints in the customer journey.
Q. How do first-party and zero-party data improve tracking accuracy?
Combining declared preferences with real behavioral signals helps brands validate intent, reduce wasted ad spend, and send cleaner events to Google, Meta, TikTok, and Microsoft Ads.
Q. How does Conversios help with first-party and zero-party data?
Conversios provides accurate GA4 tracking, server-side tagging, and clean conversion APIs, which ensures that first-party events are reliable and zero-party insights can be used effectively.