CM3 ROAS: Contribution Margin Return on Ad Spend

Track CM3 ROAS for your Shopify store. Measure contribution margin return per dollar of ad spend.

CM3 ROAS measures how much contribution margin (after marketing) you earn for every dollar spent on advertising.

Formula

CM3 ROAS = CM3 ÷ Ad Spend

Formula Components

Metric	Definition
CM3 (Contribution Margin)	Profit after COGS, fulfillment, and marketing
Ad Spend	Total advertising spend across platforms

Metadata
Type	Multiplier
Data Source	Shopify, Meta Ads, Google Ads
Aggregation	Ratio

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Example

Your Shopify store has $42,500 CM3 and spent $25,000 on advertising.

Component	Value	Calculation
CM3	$42,500	Contribution margin
Ad Spend	$25,000	Advertising cost
CM3 ROAS	1.7x	$42,500 ÷ $25,000

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How It Works

CM3 ROAS shows how much contribution margin your advertising generates after all variable and marketing costs. A 1.7x CM3 ROAS means every ad dollar produces $1.70 in contribution margin—profit available to cover fixed costs.

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When to Use

Scenario	Action
Measuring true ad profitability	CM3 ROAS shows margin after marketing costs
Setting efficiency targets	CM3 ROAS > 1x means positive contribution margin
Campaign optimization	Focus on campaigns with highest CM3 ROAS
Profitability modeling	Use CM3 ROAS for break-even analysis

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Related Metrics

Metric	Relationship
CM2 ROAS	Variable margin per ad dollar
CM4 ROAS	Operating profit per ad dollar
ROAS	Revenue per ad dollar

See all Performance metrics →