> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Returning Customer CM4 %: Repeat Order Operating Margin

> Track Returning Customer CM4 percentage for your Shopify store. Measure operating profit margin from repeat buyers.

<Tip>
  RC CM4 % measures the percentage of returning customer net revenue that becomes operating profit after all costs.
</Tip>

## Formula

<Info>
  **RC CM4 %** = ( **RC CM4** ÷ **RC Net Revenue** ) × 100
</Info>

### Formula Components

| Metric                                                                                 | Definition                           |
| -------------------------------------------------------------------------------------- | ------------------------------------ |
| [**RC CM4**](/reference/metrics/orders/contribution-margin/returning-customer-cm4)     | Returning customer operating profit  |
| [**RC Net Revenue**](/reference/metrics/orders/revenue/returning-customer-net-revenue) | Net revenue from returning customers |

| Metadata        |                                                                      |
| --------------- | -------------------------------------------------------------------- |
| **Type**        | Percentage                                                           |
| **Data Source** | [Shopify](/sources/shopify), [Upstack Costs](/sources/upstack-costs) |
| **Aggregation** | Ratio                                                                |

***

## Example

Returning customers generated **\$13,000** CM4 from **\$75,000** net revenue.

| Component      | Value     | Calculation               |
| -------------- | --------- | ------------------------- |
| RC CM4         | \$13,000  | Operating profit          |
| RC Net Revenue | \$75,000  | Revenue base              |
| **RC CM4 %**   | **17.3%** | \$13,000 ÷ \$75,000 × 100 |

***

## How It Works

RC CM4 % shows the operating profit margin from returning customers. This is typically higher than NC CM4 % since repeat orders don't carry acquisition costs. The difference between RC CM4 % and NC CM4 % reveals how much retention improves profitability.

***

## When to Use

| Scenario                      | Action                                       |
| ----------------------------- | -------------------------------------------- |
| Benchmarking retention value  | Compare RC CM4 % to NC CM4 %                 |
| Tracking retention efficiency | Monitor RC CM4 % trends over time            |
| Validating retention spend    | Ensure loyalty programs don't erode RC CM4 % |
| Profitability modeling        | Use RC CM4 % for LTV calculations            |

***

## Related Metrics

| Metric                                                                             | Relationship                            |
| ---------------------------------------------------------------------------------- | --------------------------------------- |
| [RC CM4](/reference/metrics/orders/contribution-margin/returning-customer-cm4)     | Dollar amount that RC CM4 % is based on |
| [NC CM4 %](/reference/metrics/orders/contribution-margin/new-customer-cm4-percent) | Operating margin for new customers      |
| [CM4 %](/reference/metrics/orders/contribution-margin/cm4-percent)                 | Overall operating margin                |

[See all Contribution Margin metrics →](/reference/metrics/orders/contribution-margin)