Returning Customer MER (Gross Sales): Retention Gross Efficiency

Returning Customer MER (Gross) measures what percentage of your returning customer gross sales (before discounts and refunds) is spent on advertising.

Formula

RC MER (Gross) = ( Total Ad Spend ÷ RC Gross Order Sales ) × 100

Formula Components

Metric	Definition
Total Ad Spend	Combined advertising spend across all connected platforms
RC Gross Revenue	Gross order sales from returning customers before discounts/refunds

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

Example

Your Shopify store generated $130,000 in returning customer gross sales while spending $40,000 on advertising.

Metric	Value	Calculation
Total Ad Spend	$40,000	All ad platforms
RC Gross Sales	$130,000	Before discounts/refunds
RC MER (Gross)	30.8%	($40,000 ÷ $130,000) × 100

A RC Gross MER of 30.8% means you spend $0.31 on advertising for every $1 of returning customer gross sales.

How It Works

RC Gross MER uses returning customer gross sales as the revenue base, excluding the impact of loyalty discounts or refunds. This helps you understand retention efficiency before repeat customer promotions are applied.

When to Use

Scenario	Action
Loyalty discount analysis	See MER before loyalty promo impact
Retention campaign comparison	Normalize for different discount strategies
Isolating remarketing performance	Remove promo noise from RC efficiency
Pre-discount retention cost	Understand true cost relative to intended spend

Metric	Relationship
RC MER	RC MER using total revenue
RC MER (Net)	RC MER using net revenue after discounts
MER (Gross)	Gross MER for all customers
RC Gross Revenue	The denominator in this calculation

See all Performance metrics →

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​Formula

​Formula Components

​Example

​How It Works

​When to Use

​Related Metrics

Formula

Formula Components

Example

How It Works

When to Use

Related Metrics