Postback URL

A postback URL is how one server tells another that a conversion happened. Instead of relying on the visitor's browser to load a tracking pixel, the advertiser's (or platform's) server fires an HTTP request straight to the tracking endpoint, passing the identifiers that tie the conversion back to the click that earned it. Because no browser is involved, a postback survives ad blockers, cookie restrictions, and cross-domain funnels that break pixels.

Two directions of postback

The word gets used for both ends of the chain:

• Inbound postback (advertiser → platform). The advertiser's server reports a conversion to your tracking domain — this is the server-to-server equivalent of a conversion pixel.
• Outbound postback (platform → affiliate). Your platform notifies the affiliate's own tracker when their conversion records, so their dashboard updates too.

Both are just URLs with parameters. The critical one is the click ID, which links the conversion to the exact click.

A worked example

When a visitor clicks a tracking link, the platform appends a click ID such as ll_cid=abc123 to the landing page URL. The advertiser captures that value and stores it against the order. When the order completes, the advertiser's server fires:

https://track.yourbrand.com/conv?ll_cid=abc123&txn=order-8837&event=2&rev=250
        

Here txn is the transaction ID (for deduplication), event names which action converted, and rev reports the sale amount. The platform looks up click abc123, copies its affiliate onto the conversion, and credits $250 in revenue — no pixel, no cookie required.

Postback vs pixel

A pixel is easy to install (drop an <img> tag on a thank-you page) but depends on the browser and can be blocked. A postback is fired by your server, so it is reliable and lets you send private data (email, phone) in a POST body instead of a URL. Serious integrations use postbacks for exactly this reason.

How this works in LimeliJourney

LimeliJourney's tracking generates the exact postback URL for you — never hand-write it. Open Tracking Links, pick the offer and event, and copy the ready-made server-to-server example with the IDs filled in. Fire it at your own tracking domain (the domain identifies your account), pass ll_cid to attribute it to a click, and always send a txn so retries collapse onto one conversion instead of double-counting. A server fire that adds &format=json gets back a small acknowledgement — {"ok":true,"conversion_id":12,"status":"converted"} — that you can store in your CRM and reconcile against later. Every attempt, credited or not, lands in the Pixel Log with the exact reason, so a misfiring postback is diagnosable in seconds.