Marketers have been “preparing for the cookieless future” for half a decade. In 2025, that future isn’t coming — it’s here. Chrome’s deprecation, iOS tracking limits, and escalating privacy regulation have turned first‑party and zero‑party data from a nice-to-have into the backbone of profitable growth. The winners now are those who treat data collection as a value exchange and data activation as a governed, cross‑channel operating system.