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.
A sub-ID is a query-string parameter you control, separate from your affiliate tag. Amazon uses tracking-ID variants (tag=yourname-yt-20). Awin uses clickref. ShareASale uses afftrack. Impact supports subid1 through subid5. CJ uses sid. The value you assign is free-form; the network records it with every click and conversion and lets you slice reports by it.
The reason sub-IDs matter is that without them, you have one revenue number per affiliate program and no way to attribute it. With a disciplined naming scheme (yt-rev-xm5 for the Sony XM5 review video, nl-weekly-jan26 for the January 2026 newsletter), you can answer questions like "is my newsletter actually outearning my YouTube reviews on the same product?" The answer often surprises creators who skipped this step.
See also
Related terms
Affiliate 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.
GlossaryClick 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.
GlossaryLast-click attribution
The model affiliate networks use to credit commissions: whoever was the last affiliate to send a visitor before they purchased gets the commission, regardless of who introduced them to the product.
GlossaryUTM parameters
A set of query-string tags (utm_source, utm_medium, utm_campaign, utm_content, utm_term) that Google Analytics and similar tools use to attribute traffic to specific marketing efforts. Layered on top of affiliate tracking, not in place of it.