Understanding Your Click-to-Open Rate (CTOR)

Melanie Balke
March 18, 2024

Of email marketing’s many key performance indicators (KPIs), few are as flexible as the humble click-to-open rate (CTOR). This seemingly inconsequential number measures the effectiveness of your marketing strategy. It’s a small piece of your campaign monitor, but even tiny facts make big waves!

But what does it mean?

Don’t worry! I’m dedicating today’s blog post to the ins and outs of the humble click-to-open rate.

What Is a Click-to-Open Rate (CTOR)?

A manga store. “The Basics: What Is the CTOR Rate?”

I’ll start with the definition.

A click-to-open rate (CTOR) uses a percentage to illustrate the number of unique clicks your email campaigns accrued. More specifically, it compares unique interactions against unique opens. Thus, a higher CTOR percentage is better than a lower one.

Calculating your CTOR is easy. Simply divide your campaign’s clicks by its unique opens, then multiply the result by 100. The formula is (Unique clicks ÷ Unique opens) ×100.

The Click-to-Open Rate Is Not an Open Rate…

Many newcomers confuse the CTOR and open rate. Despite their similar-sounding names, these are two different KPIs.

An open rate only measures how many people opened an email campaign. It doesn’t compare that number to anything or track activity after that first click. There’s no other data to consider when tackling an open rate.

It’s Not a Click-Through Rate (CTR), Either!

Another oft-confused metric is the click-through rate (CTR).

Both figures are percentages, and both measure clicks. However, click-through rates (CTRs) measure all activity within emails, going beyond the unique metrics of a click-to-open rate.  If one person clicks the call-to-action links twice, they’ll be counted twice under your CTR but once for your CTOR.

That’s not to say your CTR is useless! The CTR measures activity in its totality, disregarding the restrictions of its cousin metric. The end result may not be an entirely accurate representation of the percentage of people clicking your links, but it shows when certain campaigns earn more clicks than others.

And Don’t Mix It Up With Conversion Rates!

Conversion rates have similar standards.

Like your CTOR, your conversion rate measures a specific interaction. Yet, like a CTR, conversion rates don’t always account for repeated interactions. Conversion rates focus on specific actions — often purchases — over clicks. More importantly, conversion, these actions must be completed to count towards the metric.

Think of it this way: CTOR measures how many people are interested in your emails. Conversion rates measure dedication and investment.

The Problem With Click-to-Open Rates

Samurai armor. “The Problem: Is the CTOR Reliable?”

Here’s the kick in the pants: Despite its utility, the click-to-open rate has gotten a massive downgrade in recent years. The once-reliable metric has become an unreliable narrator, especially when certain email service providers are involved.

The most obvious offender is Apple Mail, which added Mail Privacy Protection (MPP) features in 2021’s iOS 15. The option has since rendered open rates moot, as the server automatically opens all accepted email messages.

It seems like an audacious and hostile move, but it’s not a standalone problem. Microsoft Outlook has added similar limitations to commercial tracking. You’ll also find similar restrictions for users of Mozilla’s mail services.


All About Digital Privacy

These changes are borne upon the wings of digital privacy.

While the marketing industry has pushed for increased oversight, consumers retaliated. More recently, buyers have drawn a clear line between the relevance of their email’s content and their right to digital privacy.

The very same metrics our industry uses to determine the most effective marketing approach have become our greatest weakness.

In other words, the main goal wasn’t malicious. Internet providers are simply anticipating the upcoming wave of digital privacy reform. It’s a calculated risk that — unfortunately — hurts us as much as it benefits the customers.

The Impact of Email Privacy

Few changes have resulted in lower CTORs.

Most platforms have, instead, artificially inflated CTORs with automatic email opening.

When customers with privacy features enabled receive an email, the provider automatically opens the message. Its contents are then scanned for malware before being delivered to the inbox. This offers the customer more privacy and better security. However, it makes it harder for marketers to accurately calculate both open rates and CTORs.

Compensating for Digital Privacy Measures

So, those high open rates might be falsified.


Fortunately, there are ways to mitigate the damage. In the years since the introduction of Apple’s MPP services, marketers have found new avenues for tracking results. Clicks and actions have received more attention, and less emphasis is placed on sheer open rates.

Ultimately, comparison is the best way to combat inaccurate data. A savvy marketer can take two seemingly disparate numbers and extrapolate data from those figures. For example, a dramatically high CTOR alongside low conversion rates may indicate a lack of urgency.

4 Ways to Improve Your Click-to-Open Rate

Overlapping leaves. “Tips & Tricks: Boost Your Email Metrics.”

With that in mind, it’s time for a special treat!

I’ve discussed the basics. I’ve outlined the inner workings of the click-to-open rate. Now, I want to treat readers to some professional tips and tricks!

Aside from email marketing’s many benefits, I want to stress the (relative) simplicity of polishing those metrics. Buffing that click rate is often easier to do when you’re addressing your email list. In many ways, creating email marketing campaigns is similarly simplistic. For most, the difficult part is thinking of ideas and perfecting subject lines.

So, I’ve included four tips to help you make that click-to-open rate soar!

1. Frontload Your Content

The best email campaigns put what’s important at the beginning.

Unlike magazines or newspapers, email marketing campaigns are perceived as short-form content. Users aren’t interested in verbose explanations. They want to know what to care about and when to take action.

You can say this is a cultural shift. It may even be tied to the proliferation of mobile device usage. Either way, shorter emails are often better.

Much of this success comes from consumers’ impatient browsing habits. Few buyers will scroll to the bottom of marketing emails to save a few dollars, and even fewer will read the entire email. Most subscribers will scan your content and determine its value in seconds. Use that time wisely by placing the most important content at the beginning.

2. Pay Attention to Relevance

Similarly, an email’s performance is determined by its value.

Strive to send the most relevant and engaging emails, regardless of the topic. Emphasize quality over quantity.

The easiest way to produce more valuable content is to reduce your email frequency. Sending more than one message per week is often seen as a nuisance.

So, if email recipients would rather receive fewer messages, your next best option is increasing relevance. Take a close look at your target audience and begin developing profiles. Use these audiences to create lucrative segments and power intuitive, valuable marketing campaigns.

3. Perfect Your Call-to-Action Link

Finally, you want to amp up those click-through rates with stellar CTAs.

Think of your call-to-action link as your active subject line. It should appeal to users and tell them what to do. The best CTAs balance novelty and functionality, blending a catchy saying with clear direction.

4. Hire Professional Support

Alternatively, you can skip the hassle.

My team of hand-picked professionals is always ready to grow and nurture your business. At The Email Marketers, everyone is dedicated to crafting the most effective content. Our expertise can make your email content shine, placing you leagues beyond your competition.

See what we can do! Schedule a free strategy session and get a personalized plan to improve your email metrics.