Hey,

Quick one today, from the least glamorous corner of your business: the stock sheet.

A denim brand came to me for an audit earlier this year. The month before, the account ran around a 3 ROAS. Then it fell apart, and by the time we spoke, the founder had turned ads off completely.

They'd already tried the usual suspects: new creative, rebuilt campaigns, dark thoughts about the algorithm.

Then we looked at inventory.

Their two best-selling sizes had been sold out for weeks.

The ads featuring those sizes were still running: a video with a creator wearing XXL kept spending money while XXL didn't exist.

Ads Manager labels none of this. Revenue keeps coming in from the sizes still in stock, so the dashboard just shows a CPA that doubled for "no reason."

Your ad account is downstream of your warehouse.

Full stockouts get noticed. Partial stockouts are the dangerous kind: when only your best-selling variant is gone, the machine keeps spending against demand that can't convert, and the ad account takes the blame.

It gets worse after the restock.

The algorithm spent those weeks optimizing toward whoever could still buy, so performance rarely snaps back the day stock returns. Founders read that lag as proof inventory wasn't the issue and go back to blaming creative.

Last month I showed you the audience version of budget drift, almost 70% of one brand's Meta budget going to existing customers. The inventory version moves faster and hides better.

One founder I work with named the feeling: "When we don't have stock, the ROAS falls out of the sky."

Their instinct is to hit stop, and it's half right, because sending people to a sold-out page is a lousy first impression. It's also expensive, because a cold account costs real money to restart.

The stock-aware setup

1. Put stock next to spend. One report: weeks of cover on your top five variants, next to ad performance in the same weekly meeting. When ROAS dips, that's the first check, before creative and before the tense call with your ad team.

2. Throttle instead of killing. When a key variant runs out, cut budgets 30 to 50%, exclude dead variants from catalog ads, and swap any creative built around them. A warm account at low spend restarts in days instead of weeks.

3. Turn the dead ends into a launch. A back-in-stock flow on email and SMS catches the demand you already paid for, so restock day becomes a revenue spike instead of a slow crawl back.

The reason this lands in August: you're deciding your Q4 inventory buy right now. That buy is an advertising decision.

Every Black Friday, brands pay the year's highest CPMs to send traffic to products that sold out on day two. Plan stock depth and the ad calendar in the same meeting.

Check your top five variants today. Ten minutes, and it might save you from firing a perfectly good campaign in November.

Talk soon,
Andrej

PS: Reply "stock" and I'll send you the three stock-aware ad rules we use with clients, copy-paste ready for your ad team, plus the back-in-stock trigger list.