Click ID
A unique identifier the affiliate network assigns to each click on your affiliate link. Used for server-to-server (S2S) postback tracking when browser cookies are unreliable, and for forensic debugging of missed conversions.
When a visitor clicks an affiliate URL, the network logs the click and assigns it a unique click ID. On Impact this is irclickid; on CJ it's cjevent; on Awin it's a hash inside the redirect. The click ID is included in the URL that lands on the merchant's site. If the merchant captures it and passes it back via an S2S postback when a sale completes, the network can attribute the conversion even without a working browser cookie.
Click IDs matter increasingly as third-party cookie support erodes in browsers. Safari has blocked third-party cookies since 2020; Firefox by default; Chrome is gradually following. S2S tracking via click ID is the modern fallback. For creators, the practical consequence is that networks with mature S2S support (Impact, CJ, Awin) lose less revenue to cookie-blocking than networks that still rely primarily on browser cookies (older ShareASale integrations).
See also
Related terms
Sub-ID
An optional label appended to an affiliate URL that lets you attribute conversions to a specific placement, content piece, or campaign. Every major network supports them; almost no creators use them well.
GlossaryCookie window
The timeframe between a visitor clicking your affiliate link and completing a purchase, during which the network will credit you the commission. Varies by program, from 24 hours (Amazon) to 30+ days (most other networks).
GlossaryAttribution window
The full timeframe during which a conversion can still be attributed to an earlier touchpoint. Broader than the cookie window in that it includes server-side and cross-device attribution mechanisms that operate beyond browser cookies.
GlossaryAffiliate tag
The unique identifier inside an affiliate URL that tells the network which publisher to credit. Different networks call it different names but the function is the same.