Learn

← Track D: Auction Economics and Identity
L4

D5

The cookie-deprecation story and Privacy Sandbox (current state)

In this lesson you will
  • Tell the accurate, current narrative: Google announced third-party-cookie deprecation, repeatedly delayed it, in July 2024 said it would not force-deprecate, in April 2025 dropped the Chrome choice prompt, and in October 2025 wound down the Privacy Sandbox initiative, while Topics / Protected Audience continued in reduced form.
  • Conclude that third-party cookies persist in Chrome for now, so identity diversification is a hedge, not an emergency.
  • Place Safari ITP and Firefox ETP in context.

You have heard "third-party cookies are going away" for years. Here is what actually happened, because the real story is now very different from the headlines, and it changes how urgently you should act.

What actually happened

  • Google announced third-party-cookie deprecation, then repeatedly delayed it.
  • In July 2024, Google said it would not force-deprecate them.
  • In April 2025, it dropped the planned Chrome choice prompt.
  • In October 2025, it wound down the Privacy Sandbox initiative, while Topics and Protected Audience continued in reduced form.

Key idea

So third-party cookies persist in Chrome for now. Identity diversification is a hedge, not an emergency. Build it deliberately, not in a panic, and be skeptical of any vendor still selling cookie-apocalypse urgency.

But Safari and Firefox already blocked them

Safari ITP and Firefox ETP have blocked third-party cookies for years. A large share of traffic is already cookieless, which is why identity (the previous lesson) still matters even though Chrome kept cookies.

Quick check

Are third-party cookies gone from Chrome in 2026?

Note

A clear "where we actually are on cookies in 2026" brief is the best way to lock this in, the facts move, the principle (diversify as a hedge) does not.

Key concepts
Third-party-cookie deprecation timelinePrivacy Sandbox (Topics, Protected Audience) wind-downSafari ITP and Firefox ETPIdentity diversification as a hedge
Going deeper

To really lock this in: write a 200-word "where we actually are on cookies in 2026" brief.

Where this leads
ANALYZE

Proposed Safari vs Chrome match-rate simulation.

DEBUG

Proposed match-rate-under-cookie-loss reproduction.

Bidcliq Academy · D5: The cookie-deprecation story and Privacy Sandbox (current state)