> ## 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.

# Subscribe: Newsletter and Mailing List Events

> Track subscribe events when visitors join your newsletter or mailing list. Measure subscription funnel performance and optimize email acquisition campaigns.

<Tip>
  The total number of times visitors subscribed to a newsletter or mailing list, tracked by the Upstack pixel.
</Tip>

## Formula

<Info>
  **Subscribe** = **COUNT** ( Subscribe Events )
</Info>

### Formula Components

| Metric               | Definition                                                                 |
| -------------------- | -------------------------------------------------------------------------- |
| **COUNT**            | Aggregation function that counts each subscribe event                      |
| **Subscribe Events** | Events triggered when a visitor subscribes to a newsletter or mailing list |

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

***

## Example

Your Shopify store recorded **1,847 subscribe events** this month from paid campaigns:

| Channel    | Subscribes | Share |
| ---------- | ---------- | ----- |
| Meta Ads   | 1,016      | 55%   |
| Google Ads | 554        | 30%   |
| TikTok Ads | 277        | 15%   |

***

## How It Works

Upstack counts subscribe events fired by your pixel when visitors opt in to your newsletter, mailing list, or email marketing. Each subscription event increments the count, providing visibility into how effectively your campaigns drive email list growth.

***

## When to Use

| Scenario              | Action                                                |
| --------------------- | ----------------------------------------------------- |
| Subscribes increasing | Scale campaigns driving email signups                 |
| Subscribes dropping   | Check subscription forms, popups, or pixel setup      |
| Comparing channels    | Identify which platforms drive the most email signups |
| Building audiences    | Create lookalike audiences from email subscribers     |

***

## Related Metrics

| Metric                                                           | Relationship                                        |
| ---------------------------------------------------------------- | --------------------------------------------------- |
| [Sign Up](/reference/metrics/funnel/conversions/sign-up)         | Account registration events (vs email subscription) |
| [Lead](/reference/metrics/funnel/conversions/lead)               | Broader lead capture including subscribes           |
| [Conversions](/reference/metrics/funnel/conversions/conversions) | Total attributed conversions across all event types |

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