Email Marketing: The Four Metrics You Need to Know

Email Marketing: The Four Metrics You Need to Know

This post follows on from our primer on email deliverability metrics.

So your email marketing campaign has been delivered… what’s next?

Great! Your beautifully crafted email marketing campaign has reached the mailboxes of your subscribers. Watch on your email platform dashboard as your engagement events gain data in real-time. Especially useful to analyse are:

  • Open rate: did your email get opened?
  • Click through rate: did people click any of the buttons or links in your email?
  • Unsubscribes: did many people unsubscribe from future emails?
  • Spam Reports: did people click the ‘report spam’ button in their email client?
Email Marketer

Email Open Rates

When your email marketing campaign has been sent and people begin to open the email, your mail platform should begin to show people have opened your email. This is done once images load, which triggers an ‘opened’ email event. Since email opens are tracked by a small transparent image beacon, images need to be downloaded in a message before an open event can be fired. This is the only way that email platforms are able to track opens on emails.

Open rate is then simply calculated as:

Open Rate = Number of Emails Opened ÷ Number of Emails Delivered

When sending an email campaign, generally at least 70% of the emails will go unopened – an open rate of 30% is considered to be good. Open rates can be highly variable depending on the quality of your email, email deliverability, the industry your company is in and where you are located.

Furthermore, with email services like Gmail siphoning out marketing emails into a ‘Promotions’ tab you might find that open rates to those email addresses lower than the average.

Maximising Your Open Rate

Open rate is an important metric to note and is affected by factors like the quality of your subject line, email timing, sender name. Improve your open rates through:

  • Segmenting your contact list and tailoring your subject lines for different groups
  • Personalising your subject lines
  • Sending at the optimal time and day to maximise open rates (bearing in mind that your subscribers may be in different time zones)
  • Consider having the sender email look like a human, rather than your business name or marketing team.
  • Split tests: use A/B or split tests to get data on what subject lines, timing and sender names work best for your audience. Do this by sending multiple versions of your email to a subset of your recipients and see which version performs better. Then send the better performing version to the rest of your subscribers. Note that it’s best to choose one variable to test each time, in order to draw reliable conclusions from your results.

Click Rates

Click rates

Clicks are affected by the quality of the content in the email: how much the content resonates with your audience, how strong your call to action is, etc.

Many in the industry place importance on maximising your clickthrough rate (CTR). You can work out your CTR as:

CTR = Number of Clicks ÷ Number of Emails Delivered

However, a metric we find more useful for determining your email content quality is the click-to-open rate (CTOR). This is a ratio of the number of clicks compared to the number of emails that were opened:

CTOR = Number of Clicks ÷ Number of Emails Opened

Since clicks are an action people take upon engaging with the content in the email, focusing only on the subscribers who opened the email when looking at who clicked is far more logical than all recipients.

Maximising Clicks

So how can you maximise your number of clicks from the customers who opened your email?

  • Understand your customers and what they want: are you alleviating a pain point or value adding with your message?
  • Ensure the email is easy to read/scan over: people don’t read email the same way they’d read a news article or blog post. Make it succinct and easy to digest, with the most important information above the fold.
  • Include a strong call to action.
  • Use strong visuals to entice readers to click
  • Make it as easy as possible to click – ensure links are clearly clickable and have enough space to click on mobiles.

Don’t forget to:

  • test your email template on different devices and browsers – the more you can check, the more confident you can be in ensuring that the content appears as expected for the user.
  • conduct split tests with different email content in order to find out what content resonates with your audience.
  • include UTM tracking parameters on your email links so you can track your users in your web analytics tool (eg. Google Analytics), so you can see their full journey from email open to conversion.


It is important that if you are sending marketing messages, you offer subscribers a way to opt out or unsubscribe from your emails. In most jurisdictions, it is illegal to send commercial email without a way to opt out – see Spam Act 2003 (Australia), CAN-SPAM (US), GDPR (Europe), CASL (Canada), etc.

While unsubscribes seem like a nuisance to many marketers, they are of critical importance to monitor. Not just because it is important to stay on top of managing unsubscribes (or use an email platform that looks after them for you), but because of what the number of unsubscribes might tell you. If you notice a spike in unsubscribes following an email campaign being sent, this could be a strong indicator that your content missed the mark.

Spam Reports

Spam rage

You know you’re in trouble when your subscribers report your emails as spam. Note that spam reports differ from unsubscribes; if subscribers click ‘report spam’ instead of unsubscribe, chances are that they are already somewhat frustrated. Most common reasons for clicking ‘report spam’ on your emails are:

  • the unsubscribe option was hard to find
  • there was no unsubscribe option
  • too many steps to unsubscribe – eg. having a unsubscribe confirmation page or worse, a communications “preferences centre”
  • the recipient thinks they have already attempted to unsubscribe

Reporting spam sends a report back to the recipient’s email provider, which loops it back to the sender email client. These can often happen if unsubscribe requests are ignored and are dangerous to you as the email sender, as it can be damaging to your sender reputation.

Understanding email metrics is the first step in understanding how well your email campaigns are performing and how to drive the most value out of them. When choosing your email platform, ensure you choose one with easy to understand metrics and data so you can get the best out of your EDMs.

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