> ## 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.

# Cost per New Customer Purchase: Acquisition Efficiency

> Track cost per new customer purchase for your Shopify store. Measure acquisition efficiency and optimize ad spend per first-time buyer conversion.

<Tip>
  Cost per New Customer Purchase measures the average ad spend required to generate one first-time customer purchase, tracked by the Upstack pixel.
</Tip>

## Formula

<Info>
  **Cost per New Customer Purchase** = **Channel Spend** ÷ **New Customer Purchases**
</Info>

### Formula Components

| Metric                                                                                     | Definition                                                                   |
| ------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------- |
| [**Channel Spend**](/reference/metrics/advertising/blended/blended-spend)                  | Total amount spent on advertising across all channels                        |
| [**New Customer Purchases**](/reference/metrics/funnel/conversions/new-customer-purchases) | Total purchase events from first-time customers tracked by the Upstack pixel |

| Metadata        |                         |
| --------------- | ----------------------- |
| **Type**        | Currency                |
| **Data Source** | [Upstack Pixel](/pixel) |
| **Aggregation** | Ratio                   |

***

## Example

Your Shopify store spent **\$12,500** on ads in January and tracked **125 new customer purchases** through the Upstack pixel.

| Metric                   | Value        | Calculation                  |
| ------------------------ | ------------ | ---------------------------- |
| Channel Spend            | \$12,500     | Total ad spend               |
| New Customer Purchases   | 125          | First-time buyer conversions |
| **Cost per NC Purchase** | **\$100.00** | \$12,500 ÷ 125               |

***

## How It Works

Upstack tracks purchase events from your Shopify store and identifies first-time customers using identity resolution. The metric divides your total advertising spend by the number of these tracked new customer purchases, giving you the true cost to acquire a converting first-time buyer.

***

## When to Use

| Scenario                         | Action                                                          |
| -------------------------------- | --------------------------------------------------------------- |
| Comparing acquisition channels   | Identify which platforms deliver new customers most efficiently |
| Optimizing ad campaigns          | Reduce spend on high-cost acquisition channels                  |
| Setting CAC targets              | Use as a benchmark for customer acquisition cost goals          |
| Evaluating prospecting campaigns | Assess performance of campaigns targeting new audiences         |

***

## Related Metrics

| Metric                                                                                                         | Relationship                                 |
| -------------------------------------------------------------------------------------------------------------- | -------------------------------------------- |
| [New Customer Purchases](/reference/metrics/funnel/conversions/new-customer-purchases)                         | Denominator in this calculation              |
| [Channel Spend](/reference/metrics/advertising/blended/blended-spend)                                          | Numerator in this calculation                |
| [Returning Customer Purchase Cost](/reference/metrics/funnel/conversions/cost-per-returning-customer-purchase) | Compare acquisition vs. retention efficiency |

[See all Conversions metrics →](/reference/metrics/funnel/conversions)