# Cost per Open

Cost per Open (CPO) is an email marketing metric that measures how much you spend to successfully trigger an email open.

Cost per Open (CPO) is an email marketing metric that measures how much you spend to successfully trigger an email open. It is calculated by dividing the total cost associated with a campaign by the number of opens it generates. For example, if you had a campaign spend of \$1000 and your associated email generated 5,000 opens, then your CPO would be \$0.20. This metric is important because it allows marketers to monitor the effectiveness of their campaigns and how efficiently their spend is converted into engagement. It can also be used as a benchmark to evaluate how cost effective one list is compared to another, how responsive different lists might be, or how effective variations of content might impact results.

## Formula

CPO = Total cost associated with a campaign / Number of opens

## Example

If a campaign had a total cost of \$1000 and 5,000 opens, the CPO would be calculated as: CPO = \$1000 / 5,000 = \$0.20

## Why is CPO important?

CPO is an important metric that helps marketers measure the effectiveness of their campaigns to determine how efficiently their spend is converted into engagement. This metric also allows marketers to compare lists and content variations to see which perform best, so they can make more informed decisions.

## Which factors impact CPO?

There are several factors that can impact the CPO metric, including the size and composition of the email list, the quality of the emails used in the campaigns, the timing of the campaigns, the targeting of the campaigns, the type of content used in the campaigns, and any additional creative or offers used to engage viewers.

## How can CPO be improved?

To improve CPO, marketers should focus on improving the impact of their campaigns. This can mean testing different content and delivery times to see what resonates best with their audiences, running A/B tests to compare different creative and offers, and segmenting their lists to ensure they are targeting the right users with the right message at the right time.

## What is CPO's relationship with other metrics?

The CPO metric is closely tied to other ecommerce metrics, such as Conversion Rate and Engagement Rate. This is because CPO can serve as an indicator of whether or not a marketing campaign is performing well, as campaigns with a low CPO will typically correlate with higher Conversion Rates and Engagement. Additionally, CPO can be used to measure the effectiveness of campaigns against other metrics, such as Return on Investment (ROI), which can be used to better understand the profitability of a given campaign.