Why visitors seem to vanish after a few days, and what “first-party” tracking actually changes.
What browsers do
Browsers have become strict about tracking, for good reasons. Safari, for example, limits how long scripts may keep cookies and storage, and shortens it further for visits that arrive from an ad click. Ad blockers block scripts loaded from well-known tracking addresses. Many people decline cookies on banners.
The result for marketers: a person who clicks an ad today and buys next week often looks like two different people, and the ad loses the credit.
Third party and first party
A script loaded from another company’s address, such as a tracking vendor’s server, is third party from the browser’s point of view. A script and cookie served by your own website are first party. Browsers and blockers treat the two very differently.
There are three common ways to make tracking first party:
- A tracking subdomain, such as
t.yoursite.com, pointed at the vendor. Better than a vendor address, but some browsers still notice when the subdomain’s servers aren’t your website’s. - A proxy on your own website, such as
yoursite.com/_s, that forwards to the vendor. The browser sees your own site setting its own cookie, and keeps it like any other. - Server-side events from your store or CRM, which don’t depend on the browser at all.
What first party doesn’t change
First-party tracking is not a way around consent. If a visitor refuses on your banner, that choice still applies, and a tracking tool should honour it. It also isn’t a way to identify people: the ID is a random number for a browser, not a name.
In Metric Sensei
The tag can be served from a tracking subdomain we set up for you, or from your own website: the WordPress plugin does it by itself, and other sites can use a Cloudflare Worker or Nginx rule that the admin page fills in. It follows your consent banner, including IAB TCF and GPP, and treats Global Privacy Control as a refusal for ads. See Attribution.