We all know the basics: Email marketing metrics can tell you if specific messages or campaigns are successful and help marketers understand longer-term trends such as database growth and engagement levels. They also uncover when you’re not meeting subscriber expectations through anomalies in spam complaints and unsubscribes.

But they can also be used as “diagnostic” metrics to provide insights into what is or isn’t working in your emails. In this post in my series on data from our 2019 Marketing Benchmark Report, I’ll dive into two diagnostic metrics: the click-to-open rate (CTOR) and clicks-per-clicker.

Click-To-Open-Rate (CTOR): Is your email getting any action?

The click-to-open rate excels as a diagnostic tool as it measures how effectively the content, design, and offers in your message are driving recipient clicks. The CTOR helps marketers answer the question: “Did the message effectively drive a high percentage of openers to click through?”

To calculate the CTOR on an email message, divide the number of unique clicks by unique opens. In our Benchmark Report, we identified the average (mean) CTOR at 14.1%, meaning 1 recipient in 7 clicked on the email after opening. However, the top-performing quartile of marketers achieved a CTOR of 33.5%, or 1 in 3 recipients clicking.

The “from” name (your message’s brand), subject line (current relevance) and perception of email value (message history) are the primary drivers of whether recipients open your message (open rate), but these factors also warm recipients up to potentially clicking on a link. Because the CTOR measures clicks as a percentage of opens (instead of messages delivered for the CTR), it’s a more pure measure of how the design of the message and content within the body of the message actually drives recipients to take action.

Clicks-per-clicker: understanding how content drives action

Another diagnostic metric I’m fond of is the little known “clicks-per-clicker.” While this metric is typically not a standard report found in most email marketing solutions, it can be calculated simply by taking the total (gross) number of clicks from a message and dividing it by the unique number of recipients who clicked on at least one link.

In the Acoustic benchmark report, Hospitals, Healthcare & Biotech (2.7 clicks) and Nonprofits, Associations & Government (2.3) had the highest mean clicks-per-clicker across industries. The lowest mean for this metric (1.6) was reported in five of the industries tracked. (Note: The lowest reading for this metric is 1.0.)

Clicks-per-clicker helps you understand the value and relevance of linked content in your email messages. The metric is of particular value to publishers and brands with newsletters that include links to multiple articles and content or resources. A high clicks-per-clicker ratio means that the linked copy in your message is resonating with readers and motivating them to click multiple times.

A low clicks-per-clicker ratio could mean that your newsletter has too many links that overwhelm recipients, the link descriptions or content titles might need some sprucing up, or your choice of content is simply not in synch with your subscribers. For content-focused newsletters, test combinations of the number of content links and formats (headlines, short snippets, comments, etc.) to optimize for more clicks.

Note that a low clicks-per-clicker ratio is not necessarily a negative. If your email has a single primary goal, such as to register for a webinar, write a product review, download a mobile app, or to purchase a specific product, then a ratio well below 2 is likely a good thing. So when using a metric like clicks-per-clicker, make sure you understand the goal of a message and you might need to establish your own different target ratios based on the types of messages you are sending.

So how do you use the CTOR and Clicks-Per-Clicker?

Using our benchmark numbers, here are a few suggestions for putting click-to-open rates and clicks-per-clickers ratio to work:

Measure several messages – but be sure to remove any bias by categorizing them by type of message.
Establish your average rate for each message type.
Benchmark against the Acoustic averages and top quartile metrics overall and by industry.
Analyze your actual clicks per links in several messages. Establish any patterns and trends for which types of links (e.g., CTA buttons or product photos, or text links, etc.), location, design, etc. that drive higher click-through rates than others.
Use the link analysis combined with the overall CTOR to make assumptions about content, layout, and offers that drive the highest engagement consistently.
Develop an ongoing testing and optimization program to refine your messages continually and to increase clicks and conversions steadily.

Up next in this series: Maximizing the value of Marketing Benchmark Reports, suggestions on how to get the most value out of benchmark reports and benchmarking metrics. Download our report to see how you compare to brands across industries and geographies throughout the world.

Email click metrics that uncover content and design issues