Writing
Every platform reports on itself. Meta tells you Meta worked. Google tells you Google worked. Add up what all of them claim and you have sold considerably more than you actually sold.
That isn’t fraud. It’s arithmetic. Each platform sees the slice of the journey it touched and books the whole thing. Nobody is lying. Everybody is counting the same sale.
I’ve deployed around two billion dollars in media. The number I trust least is the one the platform hands me.
Years ago I audited a large buy for a well-known brand. On paper it was spectacular. Inside the reporting, most of the impressions were cheap banners served to people who had already been to the site. The campaign wasn’t driving sales. It was standing next to sales that were going to happen anyway.
We called it drive-by attribution. The system confused being near the outcome with driving the outcome.
Here’s my prediction: AI is about to make this much worse, and it’s going to feel like an improvement.
Automated buying optimizes against the signal it can see. It cannot see the customer who was always going to buy. So it finds them, cheaply, in enormous numbers, and reports a beautiful number back to you. The dashboard is green because the system is grading its own homework, and now it grades faster.
The fix isn’t to distrust everything. It’s to know which numbers are evidence and which are self-report.
Platform-reported ROAS is a self-report. Treat it as a bid signal, not a result.
A holdout is evidence. So is a geo test, a matched-market read, a clean incrementality study. They are slower, less flattering, and they are the only numbers that survive a CFO who asks what would have happened anyway.
Triangulate. One number is an opinion. Three numbers that disagree tell you where to look.
Marketers already paid this tuition once. We spent a decade learning not to trust platform-reported ROAS, and the fix has a name: incrementality. The uncomfortable part is that AI does not exempt anyone from that lesson. It just raises the cost of skipping it.
Automate the buying. Keep the scoring.