Why "One ROAS Target" Breaks Multi-SKU Brands

"What's your ROAS target?" is the wrong question. When you have 500 SKUs with margins ranging from 25% to 70%, a single target guarantees you're losing money somewhere.

The Maths Problem

Consider two products in your catalogue:

If you set a 3x ROAS target for both, Product A is highly profitable while Product B loses money on every sale. But the blended report shows "3x ROAS" and everyone celebrates.

The Algorithm Problem

Google's algorithms don't see margin. They see conversion probability and revenue. Given a single ROAS target, the algorithm will naturally favour products that convert most reliably.

Often, those are your lower-priced, lower-margin items. They convert more easily because the purchase decision is simpler. So the algorithm bids aggressively on your margin-thin products while your high-margin items struggle for visibility.

The Blending Problem

Campaign-level ROAS is a blended average. When you report "4.5x ROAS" on your Shopping campaign, that number hides the reality:

• • 20% of SKUs at 7x ROAS (funding your profit)
• • 50% of SKUs at 4x ROAS (breaking even or slight profit)
• • 30% of SKUs at 2x ROAS (losing money on every sale)

The profitable SKUs subsidise the losers. Remove the losers, and your blended ROAS might drop, but your actual profit increases.

The Strategic Problem

Different products have different strategic roles. Your gateway product might deliberately accept lower ROAS because customer acquisition matters more than immediate profit. Your premium line should demand higher margins because the customer expects quality, not discounts.

A single ROAS target ignores these strategic differences entirely.

What to Do Instead

Calculate the minimum profitable ROAS for each SKU based on its actual margin. Then segment your campaigns to apply appropriate targets:

1. 1. Get margin data: Work with finance to understand contribution margin per SKU, including variable costs.
2. 2. Calculate ROAS floors: For each SKU, what ROAS makes it profitable after all costs?
3. 3. Segment by requirement: Group SKUs with similar ROAS requirements together.
4. 4. Apply differentiated targets: High-margin products get aggressive targets; low-margin products get conservative targets or get excluded.