What type of audience solution allows advertisers to use their own first-party signals?

Advertiser audiences are built from proprietary customer signals that a brand owns or collects. These signals can include eligible engagement records, conversion events, or uploaded audience information. In Amazon Ads planning, this audience type supports more customized segmentation than standard pre-built audiences. It is the relevant solution when campaign strategy depends on advertiser-provided inputs rather than Amazon-defined segments or page context.