What are seller-defined audiences?

Seller-defined audiences, or SDA, allow publishers and other sellers to describe audience groups using standardised classifications that advertising buyers can understand. Rather than depending on a shared individual identifier, the approach communicates information about an audience segment.

For example, a publisher might identify a group interested in travel and make that classification available to advertising buyers through supported programmatic systems.

The approach brings together:

• Audience classifications that describe the group.

• Standardised advertising signals that communicate those classifications.

• Transparency information that helps buyers understand the underlying audience data.

IAB Tech Lab renamed Seller Defined Audiences to Curated Audiences in December 2024, reflecting that audience creation can involve parties beyond sellers. Its official Curated Audiences documentation explains the specification and provides implementation resources.

Audience-based advertising does not automatically eliminate personal data processing. The information used to build a segment may still require consent or another legal basis, depending on the activity and jurisdiction.

Unlike Unified ID, which concerns identity matching, SDA focuses on communicating audience characteristics. The two concepts should not be treated as equivalent.