Open rate measures the percentage of recipients who opened your email, which helps you gauge the performance of your subject line. Click-through-rate measures the percentage of recipients who clicked through to your website, regardless if they opened the email or not.
This means 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. With this in mind, it’s logical to assume that click-through-rate isn’t the best indicator of engagement. So how do you accurately measure your email campaigns’ true level of engagement?
Cue click-to-open rate or CTOR.
Click-to-open rate (CTOR)
Click-to-open rate or CTOR measures the percentage of unique recipients who clicked through to your website after opening your email. Most email marketers prefer measuring engagement against CTOR because the metric only accounts for the recipients who opened and read their emails.
At HubSpot, our email marketing team measures their campaigns’ engagement against CTOR because it’s a clear indicator of resonance. “CTOR helps us understand and measure how our email message and CTAs are resonating and performing with our audience,” says Ari Echt-Wilson, the 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.”
According to Ari, CTOR is arguably the best metric for measuring an email campaign’s resonance. But CTOR can reveal even more insights about your email marketing -- it can also help you understand how to improve your campaigns. “If an email is never opened, then it's hard to grasp how we can move the needle in terms of engagement,” says Tova Miller, a Demand Generation Marketing Manager at HubSpot.
Click-through-rate, or CTR, is still a valuable metric to track, though, especially when you need a holistic view of your email's performance. "I look at click-through-rate to get a high level understanding of how my email performed overall," says Jordan Pritikin, a Senior Nurturing & Automation 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 of how my email performed overall."
Email Marketing Is Always Adapting
Email marketing might be one of the oldest and most established marketing channels in the digital era, but it’s always adapting, just like every other digital marketing channel. Click-through-rate or CTR reigned as the superior engagement metric for most of email marketing’s history, but click-to-open rate is the new sheriff in town -- and it can be a lot more revealing and insightful than its predecessor.
Originally published Mar 20, 2019 7:00:00 AM, updated March 26 2019