The campaign that never had a chance: broken measurement

The campaign that never had a chance: broken measurement
The most common cause of death is not the creative. It is that nobody could see what happened, so every decision was made on numbers that did not mean what people thought.
Where it breaks:
— Parameters dropped at a redirect. Identifiers vanish at one hop and every conversion becomes anonymous.
— Postbacks firing on the wrong event, or firing twice.
— Time zones misaligned between your reporting and theirs, so days never match and reconciliation looks like fraud.
— Conversions falling into a default bucket because a value was missing, making one placement look brilliant.
— A test conversion that was never cleaned out.
The habit that prevents all of it: before spending anything, push one transaction end to end and confirm it appears correctly on both sides, with the right identifiers, at the right time. Then repeat it after any change to the funnel.
Measure the measurement first. Everything else assumes it.