Why We Silently Drop Clicks for Paused Campaigns (Instead of Returning 404)

This article was originally published on Jo4 Blog.

A brand pauses their affiliate campaign. What should happen when clicks and conversions still come in?

My first instinct was "return 404 for everything." Campaign is paused, resource doesn't exist, done. That instinct was wrong.

TL;DR

Two endpoints handle inactive campaigns differently — by design. Pixel tracking returns HTTP 200 with a transparent 1x1 GIF. Postback endpoints return HTTP 400 with "Campaign is not active." The asymmetry exists because the callers are fundamentally different.