What is

first-party data?

What is first-party data?

First-party data is information a business collects directly from its own customers and visitors. It can be purchase history, email addresses from newsletters, customer service enquiries, survey responses and behaviour on your own website or app. The data is yours, and you know how it was collected.

Second-party data is another business's first-party data shared with you through a partnership. Third-party data is bought from players who collect data from many sources, and has become both less available and more controversial.

Why does first-party data matter?

Stricter privacy rules and restrictions on third-party cookies have made it harder to track and target based on other people's data. At the same time, ad platforms reward advertisers who can give them good signals.

• Better targeting: customer lists can be used for audiences and lookalikes in Google Ads and Meta.

• Better optimisation: conversion data with values gives bidding strategies more to work with.

• More relevant communication: segmentation based on actual behaviour beats guesswork.

• Less vulnerability: you are less dependent on changes at the platforms.

Examples of first-party data

• Order history and cart data from the online store.

• Sign-ups to newsletters, customer clubs or webinars.

• Quote request and contact forms.

• Behavioural data in GA4, such as which pages and products the user has viewed.

• Responses to customer satisfaction surveys and NPS.

• Data from customer service and chat.

The value increases when the sources are connected, so you see the whole customer relationship and not just individual events. A customer who has bought from the online store, opens the newsletter and recently contacted customer service should, for example, get different follow-up from a new visitor. That requires the data to be linked with a shared identifier, typically an email address or customer number.

How to work with first-party data

• Give customers a good reason to share data, such as a discount, useful content or member benefits.

• Collect the data in a CRM or a customer data platform, not spread across different tools.

• Make sure you have a legal basis and clear consent under the GDPR.

• Connect data to the ad platforms securely, for example via server-side tracking and hashed customer lists.

• Use the data actively: a customer list that sits untouched gives no value.

A common mistake is collecting as much as possible without a plan for using it. Start with the question: which decisions should the data improve? Read more about measurement and analytics.

Related terms

• Cookies: restrictions on third-party cookies have made your own data more important.

• Server-side tracking: a technical way to collect and share first-party data in a more controlled way.

• CRM: the place where much of the first-party data is collected and used.

• GDPR: sets the requirements for how first-party data can be collected and used.

See all the terms in the glossary.