When should an advertiser care most about brand halo metrics?

Brand halo metrics, such as new-to-brand (NTB) purchases, are crucial when evaluating a campaign's performance against a purchase goal. These metrics help advertisers understand if their Amazon DSP campaigns are driving incremental sales by reaching new customers rather than simply recapturing existing ones. While awareness goals focus on reach and impressions, a purchase goal demands insight into actual sales conversion and customer acquisition. Ignoring brand halo metrics for a purchase-focused campaign means missing a key indicator of long-term brand growth and the true effectiveness of ad spend in expanding the customer base.