Who Collects the Data?
The distinction between first-party and third-party analytics is about who collects the data and where it goes:
- First-party: You collect data on your own infrastructure. The analytics beacon sends data to your domain. Cookies are scoped to your domain. You own and control the data.
- Third-party: A vendor (ex: Google Analytics) collects data on their infrastructure. The beacon sends data to their domain. Cookies may be third-party cookies. They store your data alongside data from all their other customers.
The technical difference is straightforward: where does the analytical data you collect go? If sendData() goes to analytics.yoursite.com, it is first-party. If it goes to google-analytics.com, it is third-party.
Detailed Comparison
| Aspect | First-Party | Third-Party |
|---|---|---|
| Data ownership | You own it completely | Vendor stores and may use it |
| Cookie scope | Your domain only | Vendor's domain (cross-site capable) |
| Privacy compliance | Simpler — you control data flows | Complex — data leaves your control |
| Setup effort | High — build and maintain infrastructure | Low — add a script tag |
| Cross-site tracking | Not possible (your domain only) | Possible (vendor sees all their clients' sites) |
| Ad blocker impact | Usually unblocked (same domain) | Often blocked (known tracking domains) |
| Cost | Infrastructure and development time | Often perceptually "free" (you pay with data) |