> ## 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 Add Billing Info: Measure Checkout Step Efficiency

> Track how much ad spend drives each add billing info event in your Shopify checkout funnel. Measure efficiency by channel and optimize mid-funnel performance.

<Tip>
  Cost per Add Billing Info measures your average ad spend to generate one billing info submission during checkout.
</Tip>

## Formula

<Info>
  **Cost per Add Billing Info** = **Channel Spend** ÷ **Add Billing Info Events**
</Info>

### Formula Components

| Metric                                                                    | Definition                                                             |
| ------------------------------------------------------------------------- | ---------------------------------------------------------------------- |
| [**Channel Spend**](/reference/metrics/advertising/blended/blended-spend) | Total advertising spend across the selected channel(s)                 |
| **Add Billing Info Events**                                               | Number of billing information submissions tracked by the Upstack pixel |

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

***

## Example

Your Shopify store spent **\$5,000** on Meta ads this week and tracked **250** add billing info events.

| Metric                        | Value       | Calculation              |
| ----------------------------- | ----------- | ------------------------ |
| Channel Spend                 | \$5,000     | Total Meta ad spend      |
| Add Billing Info Events       | 250         | Billing info submissions |
| **Cost per Add Billing Info** | **\$20.00** | \$5,000 ÷ 250            |

***

## How It Works

Cost per Add Billing Info divides your total channel spend by the number of add billing info events tracked by the Upstack pixel. This checkout step occurs when a visitor enters their payment details during the checkout process. Lower costs indicate more efficient traffic at driving users through this critical funnel step.

***

## When to Use

| Scenario                              | Action                                                                                       |
| ------------------------------------- | -------------------------------------------------------------------------------------------- |
| Evaluating checkout funnel efficiency | Compare cost per billing info across channels to identify which drives higher-intent traffic |
| Optimizing mid-funnel performance     | High costs may indicate targeting users who abandon before entering payment details          |
| Benchmarking campaign quality         | Track changes over time to measure campaign optimization effectiveness                       |
| Diagnosing checkout drop-off          | Compare against cost per initiate checkout to isolate where spend efficiency degrades        |

***

## Related Metrics

| Metric                                                                                        | Relationship                                                     |
| --------------------------------------------------------------------------------------------- | ---------------------------------------------------------------- |
| [Cost per Initiate Checkout](/reference/metrics/funnel/engagement/cost-per-initiate-checkout) | Earlier funnel step — compare to identify where efficiency drops |
| [Cost per Purchase](/reference/metrics/funnel/conversions/cost-per-purchase)                  | Later funnel step — tracks cost to complete the transaction      |
| [Cost per Add to Cart](/reference/metrics/funnel/engagement/cost-per-add-to-cart)             | Earlier engagement step — measures top-of-funnel efficiency      |

[See all Engagement metrics →](/reference/metrics/funnel/engagement)