Sub-IDs and S2S Postbacks Explained for Casino Affiliates
Updated 27 October 2026
Most affiliates who stall at a few hundred dollars a month have the same problem: they know their total, but not where it comes from. Sub-IDs and server-to-server postbacks fix that. One tells you which placement a player came from; the other pushes each signup and deposit back into your own tracker the moment it happens. Neither is hard to set up, and both pay for themselves in the first month you use them properly.
What a sub-ID actually is
A sub-ID is a label you attach to your tracking link. The affiliate platform stores it with the click and carries it through to every event that player triggers later: signup, first deposit, further deposits, revenue. In your report, each label becomes its own row.
Say your CasinoWinner link inside your Casino Affiliates Group account looks like this (the format is illustrative):
https://track.example/c/12345?sid=review-top-bannerPut the same link in a comparison table with sid=compare-table-row2 and in your newsletter with sid=nl-oct-week4. A week later you are no longer looking at "CasinoWinner: 14 first deposits". You are looking at nine from the comparison table, four from the newsletter and one from a banner nobody notices. That is a decision you can act on.
Naming sub-IDs so they stay useful
The labels are free text, which is exactly why people make a mess of them. A few rules that hold up after a year of data:
- Source first, then placement, then variant.
tg-mainchannel-pin,seo-bonuscodes-table,yt-review-desc. Sorting the report alphabetically then groups your channels together. - No spaces, no personal data. Never put an e-mail address or a user's name in a sub-ID. Use hyphens and lower case.
- Keep a sheet. One line per sub-ID with the URL where it lives and the date you placed it. When a row goes quiet, you know which page to check.
- Don't over-split. A sub-ID per paragraph gives you rows with two clicks each and nothing to learn. Start with a handful per page and split further only where volume justifies it.
Website IDs versus sub-IDs
On our platform, each website or channel you add gets its own tracking ID, and sub-IDs live underneath it. Think of the website ID as the folder and the sub-ID as the file. A Telegram channel and an SEO site should be two websites; the pinned post and the daily drops inside that channel are sub-IDs. If you only run one site, you can still use sub-IDs to separate pages and placements.
What an S2S postback does
Your affiliate dashboard is the official record, but many affiliates run their own tracker as well: a self-hosted tool, a SaaS tracker, or a simple script writing to a spreadsheet. A server-to-server postback is a URL on your side that the platform calls when something happens to a player you referred. Because the call goes from server to server, it doesn't depend on cookies, pixels or the player's browser.
The flow, step by step:
- A visitor clicks your link. Your tracker generates a click ID (say
a8f3k2) and passes it into the affiliate link, usually as the sub-ID or a dedicated click parameter. - The visitor lands on the brand, signs up and deposits.
- The platform calls your postback URL, filling in the click ID and the event details.
- Your tracker matches
a8f3k2to the original click, so you now know the ad, keyword or post that produced that deposit.
A sample postback URL
Here is what a postback you register in the dashboard might look like:
https://yourtracker.example/postback?cid={click_id}&event={event}&brand={brand}&amount={amount}The parts in curly braces are macros. When the platform fires the postback it replaces them with real values, for example cid=a8f3k2&event=ftd&brand=zeslots&amount=50. Macro names differ from one tracker and one platform to another, so don't copy this example blindly: the exact list of available macros is shown in your dashboard when you set up the postback, and your tracker's documentation will tell you which parameter names it expects to receive.
Which events to send
| Event | Why you want it |
|---|---|
| Signup | Early signal. Lets you judge a new campaign within hours rather than waiting for deposits. |
| First deposit (FTD) | The event that matters most for CPA and for ad optimisation. If you send only one event, send this one. |
| Further deposits | Shows which sources bring players who come back, which is what drives RevShare. |
Why this matters more on a multi-brand account
With one Casino Affiliates Group account you have a link for each of the six brands: CasinoPurple, ZeSlots, CasinoWinner, YourWin24, Cas2Bet and LuckySlotPlay. Sub-IDs let you run the same placement for different brands and compare them fairly. Try ZeSlots in your top table slot for two weeks and CasinoWinner for the next two, with the same sub-ID pattern, and the report tells you which one your readers prefer. Your postback can include the brand as well, so your own tracker can split the data the same way.
That kind of testing is clumsy when every brand sits in a separate program with a separate login, which is one of the points we cover in multi-brand vs single-brand programs.
Testing your setup before you trust it
A postback that silently fails is worse than none, because you will make decisions on missing data. Before you send real traffic:
- Click your own link with a test click ID and confirm the click appears in your tracker.
- Check your postback endpoint answers with a normal success response and logs every call it receives, including the raw query string.
- Ask your affiliate manager to confirm the postback is active on the right website ID and for the events you chose.
- After the first real deposits, compare your tracker's count with the dashboard for the same day. Small timing differences are normal; a gap of half your conversions is not.
Remember that the dashboard remains the reference for commission. Your tracker is for optimising; if the two disagree, investigate, but pay attention to the platform figure when you look at earnings.
Common mistakes
Reusing one sub-ID everywhere
It defeats the purpose. If every link says sid=site, you have one row and no insight.
URL-encoding problems
Some page builders and link shorteners rewrite ampersands or strip parameters. Check the final URL a visitor actually clicks, not the one you pasted into your editor.
Forgetting old links
A page you rewrote six months ago may still carry an old sub-ID that now means something else. Your naming sheet prevents this.
Expecting the postback to fire for things it doesn't track
Postbacks send the events you configured, nothing more. If you need revenue figures, read them in the report rather than reconstructing them from deposits.
Do you need a separate tracker at all?
Not if you run one website and promote organically. Sub-IDs inside the dashboard are enough, and our guide on reading your affiliate reports shows how to use them. A separate tracker earns its keep when you buy traffic, run several sites or channels, or work with several programs and want one view of everything. If you are at that stage, AffTrackers is the tracking software our platform runs on, and we explain what it does on our AffTrackers page. Terms you meet along the way are defined in the casino affiliate glossary.
FAQ
How many sub-IDs can I use?
Use as many as you need to answer real questions. In practice a few per page or channel is plenty; split further only where traffic is large enough to show a difference.
Do postbacks work for all six brands?
Yes. One Casino Affiliates Group account covers all six brands, and postbacks are set up on your account, so conversions from any brand can be sent to your tracker. Ask your manager to confirm the setup for each website you add.
Where do I find the list of postback macros?
In your dashboard, in the postback settings. Macro names vary between platforms and trackers, so always use the list shown there rather than an example from a guide.
Will my tracker's numbers match the dashboard exactly?
Usually close, rarely identical, because of timing and failed calls. The dashboard is the reference for commission; use your tracker to optimise.