Click-to-Open Rate - The Best Measurement of Email Engagement


For 2021, Webbula is launching a series of blog posts about email marketing metrics. We have a variety of esteemed authors from the email industry lined up to participate. 

Previous articles you may have missed: 

  • Understanding and Leveraging the Power of Open and Click Reach Rates in Email Marketing by Jeanne Jennings. View that here.
  • Email as a Conversion Tool: 5 Metrics You Should Be Tracking by Tejas Pitkar. Read now.
  • Inactive Email Subscribers: Measure and Minimize Instead of Reactivating by Loren McDonald. Read it here. 
  • 6 Ways Customer lifetime Value Can Drive Email Marketing Strategy by Emma Warrillow and Tammi Miller. Read it. 
  • Email Deliverability Guide: How to Interpret Delivery, Clicks, and Opens. Read it. 
  • The Surprising Link Between Major League Baseball and Email Marketing Metrics by Chris Marriott. Read it Now

  • Email Metrics to Replace Open Rates After the iOS 15 Update by Dela Quist. Read it. 
  • Open Rates Aren't Perfect: How to really know if your emails are engaging by Emily McGuire. Read it now. 

Watch the discussion here! 

Metrics - Click to Open Rate

I’ve found that email marketers have strong opinions about click-through rates versus click- to-open rates and I’m no different from the rest. If you’re not familiar with the difference between the two, click through rate is the measurement of unique clicks over delivered and click -to -open rate is unique clicks over unique opens. 


Click Through Rate = Clicks/Delivered * 100

Click to Open Rate = Unique Clicks/Unique Opens * 100


Personally, I prefer click- to- open rate over click-through rate because I think it’s a greater determinate of the engagement with your email. Additionally, click- through rate measures the number of clicks over the number of emails delivered – what this doesn’t account for is whether the message landed in the inbox or in a SPAM folder. Typically, the delivered count your ESP provides you is confirming messages were handed off, not where they were placed. By using the  delivered rate to measure your clicks you may not be looking at a full picture. 

In this HubSpot blog post they mention that, “a low open rate can dilute your click-through rate, even if a large percentage of the recipients who opened your email clicked through to your website … your click-through rate may not be the best indicator of engagement.” Since open rate is what we traditionally use to determine engagement for audience selection, people who have opened in the last 12 months, why would we use a metric that omits this in factoring our email’s engagement? 

"It is important to monitor your CTOR to see whether your content actually resonates with your email subscribers. Even if CTOR is not perfect, it's better than only tracking opens or CTR, because it adds context that helps you understand the level of engagement in your list, and it can help guide your content decisions." - Constant Contact 

That said, click-to -open rate is an excellent measurement for the overall performance of an email campaign because it factors in not just the content of your email, but also the subject line and preheader. Now, I’m not advising you ignore the other metrics, but if you want a quick gut check of Did my email perform well? then it is the metric I’d lean towards. 

How do I know if I have a good Click-to-Open Rate?

When testing the content of your email, click-to-open rate is also the metric you want to focus on as it is only looking at the clicks openers did. According to this post by emma, a “good” click-to-open rate is 10-15%. While there are benchmarks for all metrics, I recommend you benchmark against yourself first and use industry benchmarks as a reference point only. 

How can I improve my Click-to-Open Rate?

The answer to improving any email metric is testing first. Every audience for every brand is different and you must measure your own subscribers’ to ultimately determine what they like. I suggest testing the following to improve your click-to-open rate once you have set your own benchmarks:

  1. Buttons versus text links – particularly if you’re using images for buttons. If the subscriber has images turned off, your button will be missing and they cannot click through. Alternatively, testing live text on the buttons so that something will appear. 
  2. Email copy – is it compelling? Are you saying too much that eliminates the need for someone to click through to your site?
  3. Email design/layout – is your CTA waaaaaaayyyyy down below “the fold”? Test bringing it up closer to the top. Is your email optimized to be viewed on different devices and clients and mobile friendly? Using Email on Acid’s Campaign Precheck can help you here. 

While there are many important email metrics, I find click-to-open rate to be the one that I prefer as it encompasses several email metrics into one for an excellent decider of engagement. 

Let me know which metrics are your “go to” email metrics by reaching out to me on Twitter. Have questions or thoughts?

Join the discussion on this article on Wednesday, May 26th at 12 PM ET with the author Betsy Grondy, Tejas Pitkar, from Netcore Solutions, and Jenna Devinney from Webbula. 



About the author

With a decade of email marketing experience, Betsy Grondy has led email strategy and execution across more than 36 countries (for local brands as well as Fortune 500 companies) all from the comfort of her North Carolina home.

As Email on Acid’s Senior Email Marketing Manager, she’s enjoying being meta in email marketing and striving for email perfection in every send. When she’s not pushing the boundaries as an #emailgeek, you’ll find her scouring flea markets with her husband, looking for cool vintage toys and mid-century modern furniture to restore.

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