New Customer MER (Net Sales): Acquisition Net Efficiency

New Customer MER (Net) measures what percentage of your new customer net sales (after discounts and refunds) is spent on advertising.

Formula

NC MER (Net) = ( Total Ad Spend ÷ NC Net Order Sales ) × 100

Formula Components

Metric	Definition
Total Ad Spend	Combined advertising spend across all connected platforms
NC Net Revenue	Net order sales from new customers after discounts/refunds

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

Example

Your Shopify store generated $70,000 in new customer net sales while spending $40,000 on advertising.

Metric	Value	Calculation
Total Ad Spend	$40,000	All ad platforms
NC Net Sales	$70,000	After discounts/refunds
NC MER (Net)	57.1%	($40,000 ÷ $70,000) × 100

A NC Net MER of 57.1% means you spend $0.57 on advertising for every $1 of new customer net sales actually collected.

How It Works

NC Net MER uses new customer net sales as the revenue base, accounting for welcome discounts, first-order promos, and refunds. This gives you the most accurate view of acquisition efficiency relative to revenue actually kept from new customers.

When to Use

Scenario	Action
True acquisition cost analysis	Include discount and refund impact
Heavy welcome offer strategies	See real MER after promo impact
High first-order refund rates	Understand true marketing cost
Setting break-even CAC targets	Ensure NC MER allows for positive margins

Metric	Relationship
NC MER	NC MER using total revenue
NC MER (Gross)	NC MER using gross revenue
MER (Net)	Net MER for all customers
NC Net Revenue	The denominator in this calculation

See all Performance metrics →

⌘I

​Formula

​Formula Components

​Example

​How It Works

​When to Use

​Related Metrics

Formula

Formula Components

Example

How It Works

When to Use

Related Metrics