Emails per Subscriber

Emails per Subscriber (EPS) helps measure the number of emails sent to each customer of an ecommerce store over a period of time.

Emails per Subscriber (EPS) is an important email marketing metric that helps measure customer engagement. EPS shows the average number of emails you have sent to each of your subscribers over a period of time.


The formula used to calculate the metric is "Total Email Delivered / Total Subscribers".

Having a good understanding of your EPS rate helps you determine how engaged your subscribers are with your emails and if they are receiving too much, not enough or just the right amount.


Let’s say an ecommerce store has 10,000 subscribers and they have sent out a total of 200,000 emails during a designated period. Their EPS rate would be 20 (200,000/10,000 = 20) which means they sent out an average of 20 emails per subscriber during that period.

Why is Emails per Subscriber important?

Emails per Subscriber is an important metric that can help measure the customer engagement rate of a store. If you send too many emails to a customer, they will become overwhelmed and less likely to engage with your emails or your store in general. Similarly, if you don’t send enough, they are less likely to be aware of your offerings or discounted prices. A good EPS rate helps maintain a balance between sending the right number of emails to your customers.

Which factors impact Emails per Subscriber?

You can improve your EPS rate by segmenting your subscribers into different categories depending on their behavior. For example, you could segment them into ones who haven’t opened an email in the last few weeks, ones who have opened but not clicked, and ones who have consistently opened and clicked your emails. This way you can customize your emails to each segment and send the right number of emails according to their engagement levels.

How can Emails per Subscriber be improved?

There are a number of factors that can impact Emails per Subscriber. The most important factor is the email list size. If your email list size is small, the ratio of emails to subscribers is likely to be higher than if your list size was larger. Other factors include your email frequency, content quality and relevancy, the design of the emails, and how well you segment your list.

What is Emails per Subscriber's relationship with other metrics?

The Emails per Subscriber metric is closely related to other ecommerce metrics such as open rate, click-through rate, conversion rate, and revenue. A good EPS rate can help boost your other metrics, whereas a high EPS rate can decrease your other metrics. Therefore, it is important to keep track of your EPS rate and ensure it stays within an optimal range.

Request Demo