New Customer CM3 MER: First-Order Contribution Margin Efficiency

New Customer CM3 MER measures how much contribution margin (after all variable costs including ad spend) you generate from first orders per dollar of ad spend.

Formula

New Customer CM3 MER = New Customer CM3 ÷ Ad Spend

Formula Components

Metric	Definition
New Customer CM3	Contribution margin from first-time buyer orders
Ad Spend	Total advertising spend

Metadata
Type	Ratio
Data Source	Shopify, Advertising Platforms
Aggregation	Ratio

Example

Your Shopify store generates $7,000 CM3 from new customers and spends $15,000 on ads.

Component	Value	Calculation
New Customer CM3	$7,000	First-order contribution margin
Ad Spend	$15,000	Marketing cost
New Customer CM3 MER	0.47	$7,000 ÷ $15,000

How It Works

New Customer CM3 MER is often below 1.0 because first-order contribution margin already includes ad spend as a deduction. This ratio shows how efficiently you’re acquiring customers at the fully-loaded variable cost level.

Interpretation

Scenario	Meaning
CM3 MER > 0	First orders contribute positively after all variable costs
CM3 MER = 0	First orders break even on variable costs
CM3 MER < 0	First orders lose money on variable costs

First-order CM3 MER is often low; profitability depends on repeat purchases.

Metric	Relationship
New Customer CM3	Numerator (contribution margin)
CM3 MER	Overall CM3 efficiency
New Customer CM4 MER	After fixed costs

See all Performance metrics →

​Formula

​Formula Components

​Example

​How It Works

​Interpretation

​Related Metrics

Formula

Formula Components

Example

How It Works

Interpretation

Related Metrics