> ## 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.

# New Customer MER (Net Sales): Acquisition Net Efficiency

> Track new customer marketing efficiency using net sales. Understand what percentage of new customer net revenue is spent on ads.

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

## Formula

<Info>
  **NC MER (Net)** = ( **Total Ad Spend** ÷ **NC Net Order Sales** ) × 100
</Info>

### Formula Components

| Metric                                                                           | Definition                                                 |
| -------------------------------------------------------------------------------- | ---------------------------------------------------------- |
| **Total Ad Spend**                                                               | Combined advertising spend across all connected platforms  |
| [**NC Net Revenue**](/reference/metrics/orders/revenue/new-customer-net-revenue) | Net order sales from new customers after discounts/refunds |

| Metadata        |                                                                                                   |
| --------------- | ------------------------------------------------------------------------------------------------- |
| **Type**        | Percentage                                                                                        |
| **Data Source** | [Shopify](/sources/shopify), [Meta Ads](/sources/facebook-ads), [Google Ads](/sources/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 |

***

## Related Metrics

| Metric                                                                         | Relationship                        |
| ------------------------------------------------------------------------------ | ----------------------------------- |
| [NC MER](/reference/metrics/orders/performance/new-customer-total-mer)         | NC MER using total revenue          |
| [NC MER (Gross)](/reference/metrics/orders/performance/new-customer-gross-mer) | NC MER using gross revenue          |
| [MER (Net)](/reference/metrics/orders/performance/net-mer)                     | Net MER for all customers           |
| [NC Net Revenue](/reference/metrics/orders/revenue/new-customer-net-revenue)   | The denominator in this calculation |

[See all Performance metrics →](/reference/metrics/orders/performance)