4 ms·
You click on a tracking link, Server 1 now has a unique ID associated with that click. S1 forwards you to S2 with a unique identifier. S2 now has that unique ID
by luckylion 4y ago
You click on a tracking link, Server 1 now has a unique ID associated with that click. S1 forwards you to S2 with a unique identifier. S2 now has that unique ID associated with you. You buy something on S2. S2 sends a request to S1 saying "unique ID #123 bought something for $40".