Ep 10: Cookies 101

Myth. Chrome killed third-party cookies. In twenty twenty-six, they still work.

A cookie is a small file a website stores in your browser.

A reader visits recipes.example. The site sets a first-party cookie, from its own domain, to remember her login. An ad company on the page, say ads.example, sets a third-party cookie. When she later visits news.example, the same ad company reads it again. That’s how buyers recognize one person across sites. Safari has blocked these by default since twenty twenty, and Firefox walls them off per site. Chrome announced a phase-out in twenty twenty. In twenty twenty-four, Google switched to user choice instead. In twenty twenty-five, it dropped the choice prompt and retired most Privacy Sandbox replacements. So Chrome still allows third-party cookies by default.

Check your browser split in analytics. Your Chrome traffic is where third-party cookies still work.

Next, why identity changes your CPM.