Affiliate tag

The affiliate tag is the part of the URL the network uses to attribute clicks to your account. Amazon calls it tag (?tag=yourname-20). Awin calls it awinaffid plus awinmid for the merchant. Webgains uses clickref. ShareASale uses afftrack paired with aff_id. CJ uses pid. Impact and Partnerize use opaque handshake URLs that contain the publisher's identity rather than a named tag parameter. The parameter name varies wildly; the role is identical.

Tags are locale-bound. An Amazon Associates -20 US tag does not work on amazon.nl, amazon.de, or amazon.co.uk. Each Amazon locale has its own Associates programme with its own tag suffix (-21 for many EU stores, country-specific for others). The same applies to Awin: a UK merchant approval does not extend to that merchant's German storefront on a different domain. If you operate across regions you maintain a separate tag per region and your link-management system needs to know which one to use per destination.

Tags are case-sensitive and exact-match. tag=YourName-20 is not the same as tag=yourname-20. Most networks normalise on lowercase, but mixed-case tags fail silently with no error. Trailing whitespace, accidental URL-encoding (%20 for a space), and truncated tags (caused by character-limit fields in some CMS systems) all fail in the same way: the network treats the visit as anonymous and pays nothing.

The tracking-ID variant pattern. Amazon lets you create up to 100 tracking IDs per Associates account, each with its own tag suffix (yourname-yt-20, yourname-blog-20, yourname-nl-20). Each ID earns separately, reports separately, and lets you slice performance by placement. This is Amazon's equivalent of a sub-ID and the only built-in way to attribute revenue per channel inside the Associates ecosystem.

The silent-failure mode: tag stripping in redirect chains. The most common failure of affiliate tags is not malformation, it is removal somewhere in the redirect chain between your click and the final destination. A merchant that runs track.merchant.com/click → www.merchant.com/product may strip query parameters at the second hop. A geo-redirector that detects the visitor's country may rewrite the URL and drop your tag. Cloudflare workers, A/B-testing redirects, and link-cleanup middleware can all do this. Your link still works (returns 200 OK, lands on the product), but the tag never reaches the network and the visit is uncredited. Affiliate tag stripping is the silent revenue leak that no uptime checker catches.

How to verify your tag survives. Open your affiliate link in a private/incognito window, watch the full redirect chain in browser dev tools (Network tab), and confirm the final URL still contains your tag. If your network supports a "tracking test" tool (Amazon Associates, Awin, Impact all do), run it. If you publish across many platforms, automated affiliate-link monitoring with tag-presence checks is the only scalable way to catch silent strips.