Definition
First-party tracking uses cookies that are set by your own domain rather than by an external tracking domain. Because the cookie comes from the same site the visitor is browsing, it is treated as trusted by browsers. This is critical because every major browser now restricts or blocks third-party cookies, which are cookies set by domains other than the one the visitor is on.
How it works
When a visitor clicks an affiliate link, your tracking system sets a cookie on your own domain, for example trck.yoursite.com, that stores the affiliate ID and click timestamp. Since the cookie originates from a subdomain of your site, the browser treats it as first-party and does not block or expire it prematurely.
The technical setup usually involves pointing a subdomain like trck.yoursite.com to your tracking platform via a CNAME DNS record. This makes the tracking requests appear to come from your own infrastructure. When the visitor later converts, your site reads the first-party cookie, retrieves the affiliate ID, and reports the conversion.
Contrast this with third-party tracking, where a cookie from tracking-company.com is set while the visitor is on yoursite.com. Browsers like Safari cap these cookies at 24 hours or block them entirely. Chrome is heading in the same direction.
Why it matters
The death of third-party cookies is not a future event. It is happening now. Safari and Firefox already block them aggressively. If your affiliate tracking relies on third-party cookies, you are losing attribution on a significant percentage of your traffic, especially from iOS and Mac users.
First-party tracking solves this by working within the browser's trust model. Your cookies persist for the full duration of your cookie window because browsers have no reason to restrict them. This means accurate attribution, reliable reporting, and affiliates who trust your program's data.
Trcker tip
Trcker uses a custom tracking domain on your own site via CNAME setup, so all cookies are first-party and unaffected by browser privacy restrictions.