> ## 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 Search: Ad Spend Efficiency for Search Events

> Track your cost per search event to measure ad spend efficiency. See how much you pay for each search interaction tracked by Upstack Pixel.

<Tip>
  Cost per Search measures how much ad spend is required to generate one search event on your site.
</Tip>

## Formula

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

### Formula Components

| Metric            | Definition                                               |
| ----------------- | -------------------------------------------------------- |
| **Channel Spend** | Total advertising spend across all connected ad channels |
| **Search Events** | Total search interactions tracked by the Upstack pixel   |

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

***

## Example

Your store spent **\$5,000** on ads last month and tracked **2,500 search events** from visitors using your site search.

| Metric              | Value      | Calculation            |
| ------------------- | ---------- | ---------------------- |
| Channel Spend       | \$5,000    | Total ad spend         |
| Search Events       | 2,500      | Total searches tracked |
| **Cost per Search** | **\$2.00** | \$5,000 ÷ 2,500        |

***

## How It Works

Cost per Search divides your total channel ad spend by the number of search events tracked by the Upstack pixel. This gives you the average cost to generate one search interaction. Lower values indicate more efficient ad spend in driving engaged visitors who actively search for products.

***

## When to Use

| Scenario                            | Action                                                           |
| ----------------------------------- | ---------------------------------------------------------------- |
| High search volume, low conversions | Investigate search result quality and relevance                  |
| Rising cost per search              | Review ad targeting to attract more intent-driven visitors       |
| Comparing channels                  | Identify which ad platforms drive engaged searchers efficiently  |
| Funnel optimization                 | Compare against other engagement costs like Cost per Add to Cart |

***

## Related Metrics

| Metric                | Relationship                                  |
| --------------------- | --------------------------------------------- |
| Search Events         | The denominator in this calculation           |
| Channel Spend         | The numerator—total ad spend across channels  |
| Cost per View Content | Another engagement cost metric for comparison |
| Cost per Add to Cart  | Measures efficiency at a deeper funnel stage  |

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