Data collected directly by a brand from its own customers through owned channels websites, apps, loyalty programs representing the highest-quality, most privacy-compliant input for enrichment.
Because it’s collected directly from a brand’s own customers with their own consent, first-party data is generally the most durable and privacy-compliant foundation for enrichment as third-party cookies and device identifiers face increasing restriction, first-party records are what alternative data gets appended *to*, rather than replaced by.
Further reading: Understanding customer data · Identity after third-party cookies
