W3C’s privacy-safe ad tool lands as China scandal guts holding firms

The W3C Attribution Reporting API specification defines a browser‑level, privacy‑first way to measure ad conversions without third‑party cookies. It aggregates conversion data with differential privacy, giving marketers and publishers a standards‑based tool that respects user privacy while preserving measurable ROI.

The recent sentencing of a former WPP Media exec in a bribery case and Meta’s aborted Manus acquisition signal that Western ad holdco’s access to China’s $9bn market is collapsing. Revenue for WPP fell 12% in Q1 and overall Chinese ad spend is shifting to e‑commerce, KOLs and platforms, leaving only a few groups like Publicis still growing.