In the 1990s, email marketing became a legitimate marketing channel, and email marketers largely measured their performance against two metrics: open rate and clickthrough rate.
Open rates measure the number of recipients who opened your email, which gives you a sense of the success of your subject line and preview. Your clickthrough rate (CTR) measures the percentage of recipients who clicked on the links in your email against the total number of subscribers who received the email.
Therefore, even if a large percentage of recipients open your email and click through to your website, a low open rate can dilute your clickthrough rate. Taking this into account, your clickthrough rate might not be an accurate indicator of engagement.
The question is, how do you accurately measure how engaged your email campaigns are? Cue the click-to-open rate, or CTOR.
The click-to-open rate determines how many unique recipients clicked on a link after opening your email. The CTOR metric is preferred by most email marketers since it only measures the number of recipients who open and read their emails.
HubSpot's email marketing team measures engagement against CTOR because it's a clear indication of success.
"CTOR helps us understand and measure how our email message and CTAs are resonating and performing with our audience," says Ari Echt-Wilson, a Conversational Marketing Manager at HubSpot and former Experiment Head of HubSpot’s Global Messaging Team. "Since the only people who see the message are the ones that open the email, it makes sense for us to measure clicks based on those who opened the email."
The formula for calculating the click-to-open rate is simple: Divide the number of unique clicks by the number of unique opens. This number is then multiplied by 100. The answer is your CTOR.
For example, you send an email to 1,000 subscribers. A total of 20 subscribers open the email and 15 click on it. The CTOR is calculated as (15/20) x 100 = 75%. The majority of subscribers who opened the email clicked on the links, indicating a very high CTOR.
It's important to count only unique opens and clicks when using this formula. For instance, if one of your subscribers opens your email in the morning and clicks on a link. Later that night, they click on the email again. That subscriber shouldn't be counted twice, as that would muddy the data. Because of this, the CTOR must only account for unique opens and clicks.
You may want to establish benchmarks for your own email campaigns now that you know how to calculate CTOR. A 2020 Campaign Monitor report found that the average click-to-open rate across all industries is 14.3%. Brands in real estate, design, and construction industries see the highest CTOR averages at 17.7%. The same report shows that food and beverage brands experience the lowest CTOR at 8.9%.
Use these numbers as benchmarks for your own campaigns.
Echt-Wilson argues that CTOR is the best metric for measuring the resonance of an email campaign. This rate can provide even more insight about your email marketing, helping your team make improvements.
It's hard to understand how we can improve engagement if an email is never opened, says Tova Miller, a Senior Marketing Manager and former Demand Generation Marketing Manager at HubSpot.
Despite this, clickthrough rate is still an important metric to track when you need a holistic view of your email's performance.
"I look at clickthrough rate to get a high-level understanding of how my email performed overall," says Jordan Pritikin, the Email and Growth Marketing Manager at HubSpot. "Since CTR accounts for deliverability, subject line performance, and how your email's content performed, it's a good metric to look at when I need a quick glance at how my email performed overall."
Whether you've tracked your CTOR for a while or plan to start, there's always room for improvement. Here are a few steps you can take to increase your CTOR:
Emails with great copy, enticing images, and compelling calls-to-action are great. In an email with a lot of text, button CTAs are great attention-getters.
Some data reports suggest that buttons can lead to higher clickthrough rates than text-based CTAs, such as "Click here for more information.". In one A/B test, Campaign Monitor saw a 28% increase in conversions by using a button instead of a text link.
When using buttons, keep these tips in mind:
Lastly, your CTA button should be prominent enough to stand out, but not so big that it hinders the overall user experience. If you’re not sure, do a squint test to make sure it’s just right.
One of the reasons why your click-to-open rate may be low is because your offers don’t align with your audience’s interests. Your subscribers may open your email, but as they scroll, none of the links appeal to them.
This can be addressed in a number of ways:
There are a few tactics you can use when it comes to email CTAs. Some brands use multiple CTAs in their emails, allowing subscribers to choose the one that interests them most. You'll often see this in emails for retail offers. The idea is that more CTAs equals more opportunities to increase CTR.
There is a drawback to this approach: choice overload. Having too many choices makes it difficult for consumers to make a decision.
With this in mind, consider testing a single CTA. By using this focused method, you may be able to increase your CTOR if there is only one desired action.
It is important to note that this approach may not be appropriate for all campaigns. A/B test, experiment, and adjust as necessary.
Email marketing might be one of the most established marketing channels in the digital era, but it’s always adapting. For most of email marketing's history, clickthrough rate reigned supreme. However, click-to-open rate is proving to be more insightful and revealing than clickthrough rate.