A btag is a URL parameter used in iGaming affiliate tracking that carries a token identifying the referring affiliate, and often the campaign and creative as well. When the visitor registers at a casino or sportsbook, the operator stores the btag on the player account, so later deposits, the FTD and all revenue from that player are credited to that affiliate.
How it works
The affiliate platform issues a tracking link. On click, it logs the visit and redirects to the operator's site with the btag appended. The site keeps the value, typically in a cookie or session, and submits it with the registration. From then on the player is usually tagged to that affiliate for the life of the account, which is what makes long-running RevShare deals possible: commission is calculated on the player's NGR for as long as the deal runs, not only on the first conversion.
The token format varies by platform. Some systems encode affiliate, campaign and creative into one opaque string; others use a plain affiliate ID.
Example
Example of a landing URL after the redirect (values are illustrative):
https://casino.example.com/welcome?btag=a12345_b678_c90
Here a12345 could identify the affiliate, b678 the banner and c90 the campaign. Affiliates usually add their own sub-ID to the tracking link as well, to see which page or traffic source produced each player.
Why it matters
For affiliates, a btag that gets dropped by a redirect chain, a cross-domain registration flow or an app install means an untracked player and lost lifetime commission. For operators, the btag is the audit trail behind every RevShare payment, so it has to survive the whole journey from click to registration. Test the full funnel on each geo and device before launch. Platforms that handle this natively are compared in iGaming affiliate software.