Returning Customer MER: Retention Marketing Efficiency

Returning Customer MER measures what percentage of your returning customer order revenue is spent on advertising. This is a key metric for understanding retention marketing efficiency.

Formula

RC MER = ( Total Ad Spend ÷ Returning Customer Order Revenue ) × 100

Formula Components

Metric	Definition
Total Ad Spend	Combined advertising spend across all connected platforms
Returning Customer Revenue	Total revenue from repeat buyer orders

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

Example

Your Shopify store generated $120,000 in returning customer revenue while spending $40,000 on advertising.

Metric	Value	Calculation
Total Ad Spend	$40,000	All ad platforms
Returning Customer Revenue	$120,000	Repeat buyers
RC MER	33.3%	($40,000 ÷ $120,000) × 100

A RC MER of 33.3% means you spend $0.33 on advertising for every $1 of returning customer revenue.

How It Works

RC MER isolates marketing efficiency for customer retention. Since returning customers are typically cheaper to convert than new customers, RC MER is usually lower than NC MER. The difference reveals how much value your existing customer base adds to blended efficiency.

When to Use

Scenario	Action
Retention marketing evaluation	Measure remarketing efficiency
Budget allocation decisions	Compare RC MER to NC MER for optimal split
Loyalty program ROI	Understand cost to generate repeat purchases
Identifying retention efficiency	Lower RC MER indicates strong customer loyalty

Metric	Relationship
MER	Total MER including all customers
RC MER (Gross)	RC MER using gross revenue
RC MER (Net)	RC MER using net revenue
NC MER	Marketing efficiency for new customers

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