Affiliate S2S tracking is postback conversion plumbing: store a click ID, receive the server message, match the join key. Pixel vs postback, then verify one real click before you scale.
PHP is free and just buy a tracker are both expensive lies. My practical breakdown of when to build your own click logger and when the maintenance tax kills your margins—no hype, just operations.
First-party tracking recovers some signals but leaves critical gaps. A failure-mode map of what server-side tags, cookies, and click IDs actually fix—and what still goes missing.
A clean /go/ slug is not compliance. Name the referee: Amazon origin visibility, Google rel=sponsored labeling, or ads destination match. Then keep an owned-domain hop honest.
