> ## 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 CM1: Repeat Order Gross Margin

> Track Returning Customer CM1 for your Shopify store. Measure gross margin from repeat buyers.

<Tip>
  Returning Customer CM1 measures the gross margin from repeat buyers—net revenue minus COGS for returning customer orders only.
</Tip>

## Formula

<Info>
  **RC CM1** = **RC Net Revenue** − **RC Total COGS**
</Info>

### Formula Components

| Metric                                                                                             | Definition                                       |
| -------------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| [**RC Net Revenue**](/reference/metrics/orders/revenue/returning-customer-net-revenue)             | Net revenue from returning customer orders       |
| **RC Total COGS**                                                                                  | Cost of goods sold for returning customer orders |
| [**customer\_type = returning\_customer**](/data-dictionary/measures-and-dimensions#customer-type) | Filters to repeat buyers                         |

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

***

## Example

Returning customers generated **\$75,000** net revenue with **\$27,000** in COGS.

| Component      | Amount       | Calculation          |
| -------------- | ------------ | -------------------- |
| RC Net Revenue | \$75,000     | Repeat buyer revenue |
| RC COGS        | \$27,000     | Product costs        |
| **RC CM1**     | **\$48,000** | \$75,000 − \$27,000  |

***

## How It Works

RC CM1 isolates the gross margin from returning customers—orders placed by customers who have purchased before. This margin comes without additional acquisition cost, making it a key indicator of retention profitability.

***

## When to Use

| Scenario                    | Action                                         |
| --------------------------- | ---------------------------------------------- |
| Measuring retention value   | Track RC CM1 as zero-acquisition profit        |
| Comparing customer segments | Benchmark RC CM1 against NC CM1                |
| Evaluating loyalty programs | Measure margin impact of retention initiatives |
| LTV planning                | Use RC CM1 to project lifetime value           |

***

## Related Metrics

| Metric                                                                                   | Relationship                             |
| ---------------------------------------------------------------------------------------- | ---------------------------------------- |
| [RC CM1 %](/reference/metrics/orders/contribution-margin/returning-customer-cm1-percent) | RC CM1 as a percentage of RC net revenue |
| [NC CM1](/reference/metrics/orders/contribution-margin/new-customer-cm1)                 | Gross margin from new customers          |
| [Returning Customers](/reference/metrics/orders/customers/returning-customers)           | Count of repeat buyers                   |

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