In a cookieless world, durable measurement depends on consented first-party identity built from data users give you directly — a login, email, or consented event captured server-side — rather than third-party cookies that browsers now block. It survives because it doesn't rely on a third party's cookie.
Every measurement system needs to know “who did what.” For two decades third-party cookies answered that. They no longer do — so identity has to be rebuilt on a foundation you actually own. For more on improving your UX, consider the impact of a fast landing page.
Why identity broke
Safari and Firefox block third-party cookies, Chrome restricts them, and consent rules limit collection. The shared identifier that stitched journeys together across the web is simply gone for most of your traffic.
Share of users where third-party cookies still work, by browser
The shared identifier is already gone for most non-Chrome traffic.
Without that shared identifier, platforms guess — and guessing shows up as inflated, duplicated, or missing conversions.
The first-party alternative
| Third-party | First-party | |
|---|---|---|
| Survives modern browsers | No | Yes |
| You own the data | No | Yes |
| Consent-aware | Partial | Yes |
| Durable over time | No | Yes |
First-party identity is built from data the user gives you directly — a login, an email, a consented event — captured server-side and tied to your own systems. It survives because it doesn’t depend on a third party’s cookie.
How we stitch identity
Done right, you get a durable, consented view of who converts — without fingerprinting or buying shady broker data.
How do you rebuild identity without third-party cookies?
We start with what the user gives you directly and consents "to": an email at checkout, a login, a form submission, captured server-side and hashed so it's durable and private. That consented first-party signal becomes the spine everything else hangs from, and because it lives in your own systems it doesn't evaporate the next time a browser tightens its rules.
From there we stitch sessions to that identity through server-side tagging and Consent Mode, modelling the gap left by users who decline rather than trying to track them covertly. The result is a measurement layer that's both compliant and complete enough for smart bidding to learn from — honest identity that survives the cookie's slow death instead of pretending it isn't happening.
This article is a spoke node connected to our core technical hubs. To explore the broader architecture, visit our primary pillar pages: