CTOR or Click-to-Open Rate in Email Marketing: Why Measure and How to Improve

Estimated reading time: 7 minutes

It is difficult to stand out in today’s email environment, when people are receiving hundreds of emails every day. A good news is that email campaigns give data that demonstrates how recipients engage with your email campaigns without the need to directly contact the customer. 

By examining your email analytics, you can understand what content is more engaging, what topics are more interesting, what time of day or what day of week is best to send the emails. This helps you improve your design, messaging, and overall strategy to create email campaigns that appeal to your audience.

In this article, we’ll focus on an important metric that should be measured by email marketers to see how well their email communications are performing: click-to-open rate or CTOR.

You can improve your email marketing strategy and establish a better connection with your audience by knowing how to analyze this data piece and what restrictions it has.

What is CTOR in Email Marketing?

CTOR is determined as the percentage of recipients who opened an email and then clicked a link within it.

Click-to-Open Rate Formula

To calculate a click-to-open rate, you divide the number of unique clicks by the number of unique opens and multiply the received value by 100.

(Unique Clicks ÷ Unique Opens) × 100

For example, if you send an email to 5,000 recipients and 1,500 open it, then 500 of those click a link, your CTOR would be 33,3% – (500 ÷ 1,500) × 100.

Why Measure Click-to-Open Rate

By tracking CTOR for your email communications you can receive important insights related to:

• Email copy formatting. If an email is opened but no link inside it is clicked, it may be a signal of a badly designed email copy: the message may be too long, boring, hard to read with an unclear call-to-action etc. 
• Effectiveness of the call-to-action. The click-to-open rate demonstrates how well your link or CTA button captures your recipient’s attention and persuades them to click it.
• Content rendering. A low CTOR may signify issues with your email copy such as broken links, missing images, or unsupported HTML elements.  
• Audience targeting. CTOR can tell whether you are targeting the right segment of your list or whether your emails comply with the subscribers’ expectations.

What Factors Affect CTOR

The main indicator of a click-to-open rate is how the email’content resonates with the reader and how appealing the email’s call-to-action is. Despite being a helpful metric, CTOR has some weak sides. It depends on various factors how accurate CTOR would be, in particular:

• Open rate calculation. Open rates may be impacted by elements such as opens in preview mode, image blocking, or plain text format. These technical particularities make open rate a less accurate metric when it comes to assessing the effectiveness of email communications. The inaccuracy of the open rate measurement entails deviations in CTOR as the latter directly depends on the open rate metric. 
• Number of links in the email. The click-to-open rate counts for unique clicks. Thus, if an email has a few links and a recipient clicks more than one link, only one click is counted for CTOR.
• Not human clicks. Link clicks generated by anti-virus tools or firewalls also count for CTOR although they don’t come from real persons.
• Unsubscribe link clicks. Clicks on the unsubscribe link don’t represent a recipient’s engagement or interest in CTA; yet they count for CTOR calculation.
• Absence of links. CTOR doesn’t stand for an effective email tracking metric for the messages without links. For email communications that don’t have a direct call-to-action, the open rate or direct recipient’s feedback may be a more effective way to measure the engagement. 

Therefore, email marketers should not rely on open rates or click-to-open rates only and are encouraged to look at a variety of email marketing metrics to have better visibility on the performance of their messages. 

Thus, additionally to CTOR and open rate, email senders should track and analyze click-through rates, conversions, bounces, complaint and unsubscribe rates, and email placement rates (Inbox vs Spam).

What Is a Good CTOR?

To understand how good your emails CTOR, you can compare your numbers with the average CTOR in your industry. According to the Statista report, in 2023 the top 5 industries with the highest CTOR included:

1. Legal services – 25,63%; 
2. Sports and activities – 18,43%;
3. Technology and high tech – 16,54%
4. Financial services – 15,4%
5. Automotive – 14,51%.

The most effective method for establishing a CTOR target is the analysis of your email campaigns metrics. For any kind of campaign, you can monitor your CTOR over time. For instance, monitor your CTOR for transactional emails, drip campaigns, promotional campaigns, newsletters, each email in an automation series, and further campaigns. You may establish an acceptable range for CTOR for your company by comparing the best and worst-performing campaigns. Then, you can set goals for improvement through creative optimizations and content.

How to Improve Your Email CTOR

Regardless of the mentioned particularities affecting the accuracy of CTOR calculation, this metric is still effective in providing insightful information about how successful your email marketing campaigns are. If you notice a decline of your click-to-open rate, here are the best practices to consider:

1. Change the Subject Line and Preheader.

Since the Subject line and preheader text are the first things a subscriber sees, they have a significant impact on whether or not an email is opened. These elements have a direct effect on the open rate, and, consequently, on the click-to-open rate.

2. Revise Email Copy.

Whether or not a subscriber interacts with the email depends on the quality, presentation, and relevance of the content. Adding personal touches to emails can help the receivers feel addressed directly. 

3. Check Content for Broken Elements.

A broken layout, invalid links, or missing pictures may turn the recipient off. It’s also important to remember that a lot of readers open the emails on mobile devices and ensure all of the elements of your email are compliant with mobile rendering.

4. Change Call-to-Action.

Subscribers are more likely to click on a link in an email if the call-to-action is clear and engaging. You can increase CTOR by encouraging your reader to interact with the content by specifying whether an offer is only available for a “limited time” or by including an expiration date or giving any other incentive to click the link.

For better user interaction, it is recommended to include one call-to-action link or button in the email to grab the reader’s attention and push them to click.

5. Segment Your Email List.

If your CTOR is declining, think about whether or not you are targeting the right audience. Try to segment your list by previous interactions or purchases to better understand your subscribers’ preferences and then create more personalized messages for each segment.

6. Test and Optimize Your Deliverability.

If your emails go to Spam, it’s unlikely that you will see a good click-to-open rate. By testing your email deliverability on a proactive basis, you can optimize your content and fix the problem elements of the copy to ensure a good Inbox placement rate. 

Furthermore, email testing reveals email reputation issues. When the email reputation is bad, even the best email template lands in Spam. By setting your email deliverability testing on auto-pilot, you can catch the moment when your Inbox rate starts dropping affecting your open rate and click-to-open rate. 

Conclusion

Different email marketing metrics are effective indicators of how well email campaigns are performing and resonating with the target recipients. CTOR or click-to-open rate determines the percentage of the recipients who clicked a link in the email out of the ones who opened the email. This metric indicates if your email content is relevant to the subscribers’ expectations and if your call-to-action is appealing to be taken. 

However, email senders should not rely on the only open rate or click-to-open rate when assessing the effectiveness of their email campaigns due to the various factors affecting the accuracy of these valuable metrics. It’s important to track and analyze a variety of data pieces to get a full picture of how well your email communications perform.  

A regular email deliverability testing will help you optimize your sending process and email copy to ensure a high Inbox placement rate. The emails delivered in the Inbox have a higher potential of being opened and clicked-through.