The affiliate glossary ↗AFFDude / Field notes
Click ID
In plain English
What does Click ID mean?
A unique token your tracker generates for each click and passes to the network so the conversion can be matched back.
The click ID (subid, clickid, tid, depending on the platform) is the thread that ties spend to revenue. Pass it in the offer URL as the parameter the network specifies; the network returns it in the postback. Lose it and your tracker shows conversions with no source.