S2S tracking (server-to-server)

Cookie-based tracking stores an identifier in the visitor's browser and hopes it is still there when the conversion happens. That hope fails often: Safari's tracking prevention expires cookies quickly, ad blockers strip pixels, and users switch from the phone where they clicked to the laptop where they deposit. In iGaming, where a player might click today, register on Thursday and deposit next week after clearing KYC, browser-dependent attribution loses conversions that actually happened.

S2S tracking removes the browser from the equation after the first click. The affiliate's platform assigns a click ID at click time and passes it to the operator in the tracking URL. The operator persists that ID against the player account it creates. From then on, every reportable event travels as a postback, a direct server call carrying the click ID back to the affiliate's platform. The full loop: click generates ID, operator stores ID, player converts, operator's server reports the event with the ID, affiliate's server matches it to the original click.

In practice, setting up S2S with a new operator means three things: appending your click ID parameter to the tracking link in the format the operator expects, registering your postback URL in their system for each event you want reported, and firing test conversions to confirm the loop closes. Skipping the third step is how affiliates discover, a month and a media budget later, that registrations were reported but FTDs never were.

S2S is not magic, it is a contract between two servers, and it is only as honest as the operator's implementation. It tells you what the operator chose to report, which is exactly why keeping your own click log matters: it gives you an independent baseline to compare their numbers against.