Definition
A postback URL is a server-side endpoint that receives conversion data directly from your backend when a customer completes an action. Instead of relying on a JavaScript pixel in the browser, your server sends an HTTP request to the tracking system's postback endpoint with the conversion details. This makes it immune to ad blockers, cookie restrictions, and page-load failures.
How it works
When a customer clicks an affiliate link, the tracking system stores a unique click ID. That click ID follows the customer through your funnel, typically passed as a URL parameter and stored in your database alongside the order. When the customer completes a purchase, your server fires an HTTP request to the postback URL with the click ID, order amount, and transaction ID.
For example, after processing an order, your backend sends: https://track.trcker.io/postback?click_id=abc123&amount=79&txn_id=order_9876. The tracking system looks up click ID abc123, finds the affiliate who drove that click, and records the conversion. No browser involvement at all.
Why it matters
Postback URLs are the gold standard for affiliate conversion tracking. They do not depend on the customer's browser, which means ad blockers, cookie expiration, Safari's ITP, and slow page loads cannot break your attribution. The conversion fires from your server, so it is as reliable as your own order processing.
For program managers, this translates to more accurate data, fewer disputed commissions, and happier affiliates. When partners trust that they are getting credit for every conversion they drive, they invest more effort in promoting your product. Undercounting is the fastest way to lose good affiliates.
Trcker tip
Trcker generates a unique postback URL for each integration, and you can test-fire it from the dashboard before going live to confirm your setup works end to end.