> ## 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 Signup Completed: Track Registration Acquisition Cost

> Track the average ad spend per completed signup. Calculate your cost per acquired registered user.

<Tip>
  Cost per Signup Completed measures the average advertising spend required to generate one successful registration.
</Tip>

## Formula

<Info>
  **Cost per Signup Completed** = **Channel Spend** ÷ **Signup Completed Events**
</Info>

### Formula Components

| Metric                                                                         | Definition                              |
| ------------------------------------------------------------------------------ | --------------------------------------- |
| **Channel Spend**                                                              | Total advertising spend across channels |
| [**Signup Completed**](/reference/metrics/funnel/conversions/signup-completed) | Total completed signup events           |

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

***

## Example

Your SaaS spent **\$15,000** on ads and generated **300 completed signups** this month.

| Channel    | Spend        | Signups Completed | Cost per Signup |
| ---------- | ------------ | ----------------- | --------------- |
| Google Ads | \$8,000      | 140               | \$57.14         |
| LinkedIn   | \$5,000      | 100               | \$50.00         |
| Facebook   | \$2,000      | 60                | \$33.33         |
| **Total**  | **\$15,000** | **300**           | **\$50.00**     |

***

## How It Works

This metric divides your total channel spend by the number of completed signups. It measures your customer acquisition cost at the registration stage, helping you understand how efficiently you're converting ad spend into new registered users.

***

## When to Use

| Scenario             | Action                                |
| -------------------- | ------------------------------------- |
| CAC calculation      | Measure cost per registered user      |
| Channel optimization | Identify most efficient channels      |
| Budget planning      | Project costs for growth targets      |
| ROI analysis         | Calculate return on signup investment |

***

## Related Metrics

| Metric                                                                                   | Relationship         |
| ---------------------------------------------------------------------------------------- | -------------------- |
| [Signup Completed](/reference/metrics/funnel/conversions/signup-completed)               | Count of completions |
| [Cost per Signup Started](/reference/metrics/funnel/conversions/cost-per-signup-started) | Top-funnel cost      |
| [Signup Completed Value](/reference/metrics/funnel/conversions/signup-completed-value)   | Value of signups     |

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