Every ad platform reports the same sale, so the numbers never add up and none of them describe the real journey. Last click, the default everywhere, hands all the credit to the final touch, so branded search and retargeting look like heroes while the channels that bring new customers look like waste.
And it is getting harder to even see. Cookie loss, device privacy changes, and ad blockers have quietly eaten a chunk of the signal, so the platforms bid on a shrinking, biased sample. Google's own tool makes it worse, below a few hundred conversions a month its data-driven model silently falls back to last click.
So the one question that matters, which channels actually bring the customers, is the one your dashboards can't answer.