Email Marketing Metrics & Improving Performance


Creating a personalised email for each recipient can boost open rates, click-through and deliverability. Your email software should make it easy to pull in customer data from your list to give each email the distinctive touch.

Optimise for Mobile

With the rise of Smartphones, the majority (51%) of email is now opened on a mobile device (Source Return Path). Optimise your email for mobile by using responsive design, which is easy to read and engaging with a clear call to action.


Once you have built an email database, segment this list into more specific groups to send separate groups targeted campaigns. For example, you should send different emails to customers at various stages of the buying cycle.

Successful segmentation will lead to fewer unsubscribes, a higher click-through rate and increased engagement as you send more relevant content to users.

A/B testing

If you send out a big email campaign, you may wish to perfect the content before sending it. A/B testing allows variations of the email to be trialed on small subsets of users (A and B) before the mail is sent to the main group of users (group C). After sending the variations, your email service provider should then tell you which performed the best using your chosen metrics.

A/B testing can be run on all aspects of an email, including subject line, content and offer type (e.g., fix amount of percentage).

Measuring performance: Email Marketing Metrics

Before launching an email marketing campaign, it is essential to understand your goals to know if your campaign is successful. Several key email marketing metrics can help you benchmark the performance of your campaigns.

List Size and Growth

The more emails collected from customers or captured from website visitors, the more extensive your email database and the more potential customers you can reach to grow sales. Your email service provider should enable you to monitor this vital metric to see how many new subscribers are added on a weekly or monthly basis.

Open Rates

The open rate is the percentage of recipients who opened the emails they received. The average rate varies by sector but is around 15-25% (Source: Campaign Monitor). The following factors influence the rate:

  • Subject line. The subject line, along with the preheader text and the sender’s name, is the first thing your recipient will see when they receive a mail and so needs to be compelling.
  • Preview text. Most email clients show preheader text next to the subject line. With most email service providers, you can control the preheader text to control the preview content seen by readers.
  • Deliver relevant content. If your open rate is below average, you may be delivering the wrong content to the wrong people.

Click-Through-Rate (CTR)

The click-through rate measures how many opened emails received at least one click through to the target website. The average click-through rate is 2-3% (source: Campaign Monitor). This should be higher than the average website conversion rate as the emails are sent to people who have opted to see your content (e.g., past website customers).

CTR is a measure of how engaging your email content is. The email content, including images and calls to action, obviously plays a significant role in performance. If your open rate is reasonable, but your CTR is low, the content is underperforming.


Email deliverability refers to the proportion of emails that end up in the recipient’s inbox instead of bouncing or classified as spam. When mailbox providers receive an email, they will run reputation checks on the email to decide whether the message is SPAM. They base this decision on their analysis of the sending email address’ historical performance, the domain, and the email’s content. Factors considered will include:

  • The reputation of the server or IP address used to dispatch the email.
  • Domain reputation of links in the content
  • Email bounce rates
  • Spam complaint rates for sender, domain, and server

To keep deliverability high, it is essential to have a good sender reputation. This is achieved by keeping your list up to date. This involves:

  • Removing old emails. If an email has not interacted in a long time, consider removing it. Remove any emails which bounce.
  • Opted-in subscribers only. Only send emails to subscribers who have given specific contact permission.
  • Quality content. Avoid the use of spammy titles, e.g., GET RICH QUICK!!!!!!
  • Unsubscribe option. Always include a clear unsubscribe option.

Be careful as many email service providers consider a 0.1% complaint rate to be the maximum acceptable threshold.


The goal of most email marketing is to drive sales. If email marketing is working well for your business, then a reasonable goal is 20% of your sales coming from this channel.


Whilst the performance of email marketing is individual to each business, an eCommerce business whose email marketing is going well might look like this:

  • 20% open rate. This indicates that you are sending relevant emails to the right people with interesting subject lines.
  • 5% click-through rate. This suggests that the content and offers in your emails are compelling enough to click.
  • 20% of website revenue from email marketing. This says email marketing as a channel is converting first-time customers and upselling existing customers enough to warrant further investment.



Published by

Leave a Reply