An advertiser for an Italian supplement brand posted the autopsy on a failed Meta campaign: about 6,500 euros spent, a 0.14 ROAS, and a metric everyone on the team had read as good news. Their CPM was around 1 euro. He says they took that as efficient buying, when in his reading it meant the algorithm was pushing budget into inventory nobody real looks at.
The strategy
Rather than another round of creative, he wrote three gates and says the rule now is that they apply before any spend goes back on.
First, a CPM floor. For their vertical the CPM has to sit in the 5 to 15 euro band. Below that band he treats the traffic as ghosts and the ad set as a placement problem rather than a creative problem. Second, a mid funnel kill rule with a deadline: cost per initiated checkout under 15 euros by day 5, or the ad set dies. Third, a reporting change: judge creatives on CPA broken out by placement, never on the account average CTR, because in his account the averages hid a large spread between placements.
His summary of the lesson is that a metric that looks good on its own can be the exact signature of the problem, and he ends by asking others what their own minimum CPM is before they get suspicious.
Why it works
A CPM is a price, and a price tells you who else wanted that impression. When nobody is bidding against you, the usual reason is that the placement does not produce buyers, so cheap reach and bad reach arrive together. Cost per initiated checkout catches the same thing earlier than purchases do, because it needs far fewer events to become readable, and a per placement breakdown shows you where the cheap impressions actually landed.
How to tell if a cheap Meta CPM is a problem
Pull the last 30 days by ad set with CPM, cost per initiated checkout and CPA, then break the same view down by placement. Write down the CPM band your profitable ad sets have historically sat in, and treat anything far below it as a flag rather than a result. Set one mid funnel gate with a date attached, in the way he uses cost per checkout by day 5, so an ad set has to prove itself before it reaches a purchase sample size. Then stop reading account average CTR entirely and compare creatives on placement level CPA.
Credit: u/Neither-Newt9129 on Reddit