> ## 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.

# MER (Net Sales): Marketing Efficiency on Net Revenue

> Track MER using net sales for your Shopify store. Measure marketing efficiency after discounts and refunds.

<Tip>
  MER (Net Sales) measures what percentage of your net order sales is spent on advertising—marketing efficiency after discounts and refunds.
</Tip>

## Formula

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

### Formula Components

| Metric                                                           | Definition                                      |
| ---------------------------------------------------------------- | ----------------------------------------------- |
| **Total Ad Spend**                                               | Combined spend across all advertising platforms |
| [**Net Revenue**](/reference/metrics/orders/revenue/net-revenue) | Order revenue after discounts and 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 spent **\$20,000** on ads and generated **\$160,000** in net sales.

| Component     | Value     | Calculation                |
| ------------- | --------- | -------------------------- |
| Ad Spend      | \$20,000  | Total advertising          |
| Net Sales     | \$160,000 | After discounts/refunds    |
| **MER (Net)** | **12.5%** | \$20,000 ÷ \$160,000 × 100 |

***

## How It Works

MER (Net Sales) uses net revenue after discounts and refunds. This is the most conservative MER calculation, showing efficiency against actual realized revenue. Higher discounts and refunds will increase your net MER versus gross MER.

***

## When to Use

| Scenario                         | Action                                              |
| -------------------------------- | --------------------------------------------------- |
| Conservative efficiency tracking | Use net MER for realistic marketing efficiency      |
| Measuring discount impact        | Compare net MER to gross MER to see discount effect |
| Profitability planning           | Net MER aligns closer with true revenue             |
| Setting efficiency targets       | Use net MER for conservative budget planning        |

***

## Related Metrics

| Metric                                                               | Relationship                 |
| -------------------------------------------------------------------- | ---------------------------- |
| [MER](/reference/metrics/orders/performance/mer)                     | MER using total revenue      |
| [MER (Gross Sales)](/reference/metrics/orders/performance/gross-mer) | MER using gross revenue      |
| [Net Revenue](/reference/metrics/orders/revenue/net-revenue)         | Revenue base for calculation |

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