First-party data

First-party data is information a business gathers directly through its own relationship with customers: website and app behavior, purchase history, CRM records, email engagement, and loyalty program activity. It is distinguished from second-party data (someone else's first-party data, shared directly) and third-party data (aggregated and sold by data brokers with no direct customer relationship).

Companies typically collect it through owned properties—sites, apps, point-of-sale systems—instrumented with tracking and forms, then unify it across sources in a customer data platform or data warehouse using an identifier like an email address or logged-in user ID. Collection and use depend on the consent captured through tools like consent mode and on the organization's broader data governance policies.

First-party data has become the most reliable asset for advertising, personalization, and modeling as third-party cookies and mobile ad identifiers have been restricted by browsers and platform policy. Its main limitation is coverage: it only exists for people who have already interacted with the business, so anonymous prospects and cross-device behavior remain gaps that first-party data alone cannot close, often pushing companies toward server-side tagging to capture more of it reliably.