> ## 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.

# Subscription Initial Purchases: First Subscription Orders

> Track first-time subscription purchases. Measure new subscriber acquisition for subscription boxes.

<Tip>
  Subscription Initial Purchases counts first-time subscription orders from new subscribers.
</Tip>

## Formula

<Info>
  **Subscription Initial Purchases** = **COUNT** ( subscription\_initial\_purchase events )
</Info>

### Formula Components

| Metric                                     | Definition                                 |
| ------------------------------------------ | ------------------------------------------ |
| **subscription\_initial\_purchase events** | Events fired for first subscription orders |

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

***

## Example

Your subscription box business tracked **423 subscription\_initial\_purchase events** in January.

| Metric               | Value | Notes                  |
| -------------------- | ----- | ---------------------- |
| All Purchases        | 2,560 | Total purchase events  |
| Subscription Initial | 423   | First-time subscribers |
| Initial % of Total   | 16.5% | New subscriber share   |

***

## How It Works

The Upstack pixel tracks subscription\_initial\_purchase events for first-time subscription orders. This distinguishes new subscriber acquisition from recurring subscriber revenue.

***

## When to Use

| Scenario               | Action                                     |
| ---------------------- | ------------------------------------------ |
| Subscriber acquisition | Track new subscriber growth                |
| Campaign attribution   | Identify channels driving new subscribers  |
| CAC calculation        | Calculate true subscriber acquisition cost |
| Cohort analysis        | Analyze new subscriber performance         |

***

## Related Metrics

| Metric                                                                                                           | Relationship                 |
| ---------------------------------------------------------------------------------------------------------------- | ---------------------------- |
| [Subscription Initial Purchase Cost](/reference/metrics/funnel/conversions/subscription-initial-purchase-cost)   | Cost per new subscriber      |
| [Subscription Initial Purchase Value](/reference/metrics/funnel/conversions/subscription-initial-purchase-value) | Revenue from new subscribers |
| [Subscription Recurring Purchases](/reference/metrics/funnel/conversions/subscription-recurring-purchases)       | Repeat orders                |

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