Marketing can't fix a broken business.
After a supply chain conference in Tokyo, I keep thinking about ROAS drops that aren't really campaign problems. In the accounts I've worked on, the fix is often somewhere else: stock, feeds, margins, delivery.
What a Tokyo conference reminded me about ROAS, feeds and the rest of the system.
One of the conferences I went to in Tokyo last month was on supply chain analytics for digital markets. It sounded far from performance marketing, but it ended up being the talk I thought about most after coming home.
The reason: in the accounts I've worked on, when ROAS drops, it's usually not the campaigns' fault.
The reflex of blaming the campaigns
When results dip, I know the first move: open the dashboards, look at the campaign. Did the bid change? Did the auction get tougher? Is there a creative issue? Is the audience saturated? These are real questions, and sometimes the answer is yes.
Often enough, though, the campaigns are doing exactly what they were doing last month and the numbers are still off. That's when I start looking somewhere else.
Things that change ROAS that aren't your campaign
A few patterns I see often:
- The best-selling product is out of stock. The algorithm keeps pushing it because it was strong, but conversions stop.
- The product feed has issues: missing GTINs, wrong prices, outdated availability. In my experience, PMax reacts badly to messy feeds.
- The margin shifted. Sales went up, but profit went down. ROAS looks fine on screen, while the business is losing money.
- Delivery times changed. Customers add to cart, then drop off at checkout because shipping went from 2 days to 7.
- A competitor undercut the price. The campaigns can't compete with what's on the landing page.
- The product page was updated and something broke in the process.
None of these are campaign problems. They're business problems showing up in marketing data.
That's what the Tokyo conference reminded me of. The campaigns sit at the end of a long chain. If anything earlier in that chain breaks, the campaigns can't paper over it.
Marketing and business data should talk to each other
For a long time, I treated marketing dashboards and business dashboards as two separate things. The marketing one had Google Ads, Meta, GA4. The business one had stock, margin, fulfilment, returns. I don't do that anymore.
The most useful dashboard I've built recently for an e-commerce client has both: ROAS sits next to stock levels, CPA sits next to current margin, each campaign is tagged with the products it pushes, and each product is tagged with its current availability. When something drops, it's much faster to figure out why.
My setup isn't perfect, and most clients still don't have everything connected. Even a partial view changes the conversation. When I can show a client that ROAS dropped at the same moment the top product went out of stock, we stop debating the campaign and start fixing the stock. Usually a cheaper fix.
PMax specifically
With PMax, I find this even more obvious. In the accounts I've managed, the feed drives almost everything: I don't choose which products get pushed, I don't choose the placements, I hand over a feed and the system decides.
So if the feed is wrong, PMax is wrong. If the feed prioritises low-margin products, that's where the budget goes. If availability data is stale, people land on out-of-stock pages. I've helped a few clients audit their feeds, and most of them found dozens of small issues. Fixing those, rather than tweaking the bidding strategy, often moved the numbers more than anything I could change inside the campaign.
The bigger point
What stayed with me from the conference is simple: marketing performance is a symptom, not the cause. If the business has a problem (stock, pricing, delivery, product quality), marketing surfaces it as bad numbers. Spending more to compensate usually makes the problem more expensive.
So when I start with a client now, I ask for more than the campaign data. I want to see stock, margin, delivery times, returns, support tickets. If any of those look off, I want to fix them first.
Takeaway
If your numbers drop and the campaigns haven't changed, look at the business behind them: the feed, the stock, the margin, the product page, the delivery promise. Better marketing isn't always about spending more; often it's about fixing what sits behind the campaigns.