New research from Fospha, a full-funnel marketing measurement platform, unveils the "halo effect"—the hidden impact of Direct-to-Consumer (DTC) advertising on third-party marketplaces like Amazon. The Halo Report highlights how platforms such as TikTok, Meta, and YouTube significantly influence Amazon sales, providing marketers with a more comprehensive way to measure return on ad spend (ROAS).

Insights from the Halo Report

• 42% of a brand's Amazon sales are driven by non-Amazon media, underscoring the cross-platform impact of advertising.
• Unified ROAS, which measures ad-driven revenue across multiple sales channels, is 45% higher than DTC-only ROAS for upper-funnel campaigns.
• TikTok exhibits the strongest halo effect, with Unified ROAS being 80% higher than single-channel DTC ROAS when Amazon revenue is factored in.

Real-World Impact: Nécessaire’s Success with Halo

Premium skincare brand Nécessaire joined Fospha’s Halo beta program to better understand the influence of their DTC advertising on Amazon conversions.

• TikTok ads generated twice the Unified ROAS compared to DTC-only ROAS.
• Meta ads showed an 87% higher Unified ROAS than their DTC-only measurement.
• With these insights, Nécessaire optimized their marketing strategy before Amazon Prime Day, outperforming industry revenue benchmarks by 47%.

Industry Implications

"For too long, marketers have been in the dark about the true impact of their DTC ad spend on Amazon sales," said Sam Carter, CEO of Fospha. "The Halo Report sheds light on this blind spot, which is more critical than ever with Amazon now capturing a third of all US eCommerce sales."

Why This Matters for Marketers in 2025

• Existing measurement tools fail to capture the true cross-platform impact of ads.
• Marketers using DTC-only ROAS are underestimating the real value of their advertising.
• A Unified ROAS approach will be essential to maximize returns and outperform competitors in 2025.