Czym jest First-party data?

First-party data is data you collect directly from your own audience through your own properties: analytics from your website, signups and product usage from your app, purchase history, survey answers, email engagement. It contrasts with third-party data, which is collected by someone else across other people's sites and bought or borrowed, historically via third-party cookies.

The distinction now carries real weight. Browsers block third-party cookies by default in most cases, and privacy law treats data bought from brokers very differently from data a customer handed you directly. First-party data is more accurate (it describes your actual customers), more durable (no browser change takes it away), and easier to justify under GDPR, though it still requires a lawful basis and honest disclosure; first-party does not mean consent-free. For most companies the richest first-party asset is logged-in product data, which supports retention and cohort analysis without any cross-site tracking.

A first-party analytics setup pairs naturally with cookieless measurement for the anonymous visitors who never log in.