> ## 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 Select Content: Engagement Efficiency Metric

> Track how much ad spend is required for each select content engagement. Measure content interaction efficiency and optimize your targeting.

<Tip>
  Cost per Select Content measures how much ad spend is required for each content selection event, helping you evaluate engagement efficiency across campaigns.
</Tip>

## Formula

<Info>
  **Cost per Select Content** = **Ad Spend** ÷ **Select Content Events**
</Info>

### Formula Components

| Metric                    | Definition                                                   |
| ------------------------- | ------------------------------------------------------------ |
| **Ad Spend**              | Total advertising spend across all channels                  |
| **Select Content Events** | Count of select\_content events tracked by the Upstack Pixel |

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

***

## Example

Your campaigns drove **12,450 select content events** with a total ad spend of **\$8,500** last month.

| Period    | Ad Spend    | Select Content Events | Cost per Select Content |
| --------- | ----------- | --------------------- | ----------------------- |
| Week 1    | \$2,100     | 3,150                 | \$0.67                  |
| Week 2    | \$2,200     | 3,300                 | \$0.67                  |
| Week 3    | \$2,000     | 2,800                 | \$0.71                  |
| Week 4    | \$2,200     | 3,200                 | \$0.69                  |
| **Total** | **\$8,500** | **12,450**            | **\$0.68**              |

***

## How It Works

The select\_content event fires when a user interacts with content elements—clicking product tiles, expanding descriptions, or selecting categories. Cost per Select Content divides your total ad spend by the number of these engagement events to show how efficiently your ads drive content interaction.

***

## When to Use

| Scenario                                      | Action                                                     |
| --------------------------------------------- | ---------------------------------------------------------- |
| Comparing content engagement across campaigns | Lower cost indicates more efficient targeting              |
| Evaluating creative performance               | High-engagement creatives reduce cost per interaction      |
| Identifying underperforming ad sets           | Rising costs may signal audience fatigue                   |
| Optimizing for mid-funnel engagement          | Balance cost efficiency with downstream conversion quality |

***

## Related Metrics

| Metric                | Relationship                                   |
| --------------------- | ---------------------------------------------- |
| Select Content Events | The denominator—total content selections       |
| Cost per Add to Cart  | Comparison metric for deeper funnel engagement |
| Cost per View Content | Alternative awareness-stage cost metric        |

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