The problem
The client had a single Performance Max campaign running across their full product catalogue. It was working — solid ROAS, 120 or more monthly conversions. They wanted to grow. The instinct was to increase the budget. That would have been a mistake.
A closer look revealed what I see constantly in catalogue-heavy accounts: a handful of products were driving the vast majority of conversion value, while hundreds of others consumed budget and returned almost nothing. Increasing spend on one mixed campaign would not fix that. It would amplify it.
In a single PMax campaign, budget allocation is a black box. Best sellers and slow movers compete for the same spend. More budget without structure just scales the imbalance.
What I did
One structural change — precise, deliberate, and immediately measurable.
Identify the over-performers
Analysed conversion value by product within the existing campaign. Identified best sellers driving a disproportionate share of revenue and kept them in the original campaign.
Create a separate PMax for everything else
All remaining products moved to a new campaign with its own budget and target. This removed noise from the main campaign and gave the rest of the catalogue a fair, independent evaluation.
Increase budget on best sellers only
Additional spend directed precisely at proven products. No guesswork. No dilution across products that had not earned the budget yet.
Why it works
Best sellers get dedicated budget
Proven products no longer compete with unproven ones for spend. Their own campaign, their own target, their own optimisation history.
The rest gets a fair test
Products invisible in a mixed campaign now generate real data. Some will prove themselves. Others will not — both are signals worth having.
Scaling becomes surgical
You choose exactly where additional spend goes. That is the difference between growth and efficient growth.
Works with the algorithm
Cleaner structure means more focused signals, faster learning, and more reliable performance over time.
Increasing budget on a mixed campaign does not scale your winners. It dilutes them. Segmentation is the unlock.
Running a single PMax across all your products?
This is one of the most common missed opportunities I see. A 30-minute call is enough to tell you whether segmentation would make a difference in your account.
Find out what your Google Ads account is really worth.
In 30 minutes I will show you exactly where your budget is being wasted and what I would do about it.
No pitch. No pressure. You will leave knowing exactly what to fix.
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