Click ID

A click ID is the single most important value in performance tracking. Every time someone follows a tracking link, the platform records the click and mints a unique ID for it. When a conversion later fires carrying that same ID, the platform looks up the click and copies its affiliate, campaign, channel, and creative onto the conversion. No click ID, no reliable attribution — everything else is a fallback.

Where the click ID lives

The click ID has to survive the journey from click to conversion, which can span days and multiple pages. It does so in up to three places:

1. On the URL. At click time the platform appends it to the landing page (in LimeliJourney, ?ll_cid=abc123), so the destination page can read it.
2. In a first-party cookie. The same value is stored in the visitor's browser on the tracking domain, as a fallback.
3. In your own system. The most robust setup captures the click ID from the URL and stores it against the order, then echoes it back on the conversion pixel or postback.

A worked example

A visitor clicks and lands on yourbrand.com/lp?ll_cid=abc123. Your landing page reads abc123 into a hidden form field. When the visitor completes checkout, your server fires:

https://track.yourbrand.com/conv?ll_cid=abc123&txn=order-77&rev=120
        

The platform finds click abc123, sees it belonged to Affiliate #34's campaign, and credits the $120 conversion to them automatically. If you had not passed abc123, the platform would fall back to the cookie — and if that were blocked or expired past the attribution window, the conversion would record as unattributed.

Why explicit beats implicit

An explicit click ID on the conversion always anchors the match, regardless of the click's age or the browser's cookie policy. The cookie fallback is convenient but fragile — Safari and Firefox may withhold cookies on shared subdomains. Passing the click ID yourself is the difference between "usually attributes" and "always attributes."

How this works in LimeliJourney

LimeliJourney's tracking appends ll_cid (and a visitor ID, ll_vid) to every redirect by default, and the pixel generator wires your snippets to capture it. You can turn URL appending off per offer and pass the click ID under your own parameter name via a redirect token instead — the cookie fallback still applies either way. The legacy cid parameter is accepted for older pixels. On your own first-party tracking domain, the cookie fallback is reliable; passing ll_cid explicitly makes attribution bulletproof.