Measuring Email Effectiveness with CTOR

measuring email with ctorEmail marketers often obsess over two parallel metrics: open rate and click through rate (CTR).

Open rate presumably lets us know how well our subject lines and other pre-inbox optimization is performing, while click through rate tells how well we did at designing the email itself.

While these numbers are important to monitor, many of us are ignoring a key metric that’s aimed at gauging the overall effectiveness of an email campaign: Click-to-open-rate.

Click-to-open-rates, abbreviated CTOR, combines measures of opens and clicks to give you a better idea of your campaign’s overall performance.

In other words, of those subscribers who open the email, how many of them actually clicked something in the email?

CTOR essentially measures the relevancy of a given email.

Did your email marketing effort in fact engage the subscriber enough for them to take that next critical step in developing a  relationship with your brand? Or did all the activity stop after the open?

How CTOR is Judged and Measured

There are lots of tools available to measure the success of an email marketing campaign, most of which report on open rate, click-through statistics, deliverability, conversion rates, and unsubscribe actions.

That’s a lot of stats, and they’re all measuring very different things. Keeping a careful eye on all of them can become overwhelming.

CTOR, however, can provide quick insight into a campaign’s overall health in a single number. Measuring CTOR gives you a clear and easy look at how your content is performing by giving you data based only on subscribers who actually open the email.

To understand the effects of CTOR, it helps to have a solid understanding of the definitions related to customer engagement:

  • Open Rate: the percentage that measures unique opens compared to the total number of messages delivered to your list.
  • Click-Thru-Rate (CTR): the number of people who clicked on your message’s link as measured against the total number of emails.
  • Click-to-Open-Rate (CTOR): the percentage of subscribers who clicked something in the email as related to the total number who opened it.

An advertisement click through rate is measured by dividing the number of times an image is clicked on by the number of times the impression was made available and represented as a percentage.

For instance, if an advertisement were delivered 100 times and clicked on three times, this results in a 3% click through rate. CTOR adds further nuance to this percentage.

CTOR combines open rate and CTR into a single metric that gives you a solid understanding of how your campaign is performing without requiring too much analysis. It also helps separate the performance of your in-email content from other factors that might otherwise color that stats, including your “From” name and subject line.

Email Marketing Best Practices and Measurement Metrics

Since open rates statistics can move around like a weather vane in a tornado, CTOR becomes a far more useful metric on which to understand customer behavior and reactions to your marketing content.

Loren McDonald of Silverpop argues that, “the CTOR lets you analyze, benchmark and diagnose design and content issues regardless of other messages’ open and click-through rates.”

Email marketing campaigns are one of the most effective outreach methods available to companies, but unless their performance parameters are adequately monitored there is no way to understand how to fine tune the message you are trying to get out to the buying public.

Benchmarks are Important Evaluation Metrics

When determining whether your CTOR rates are approaching acceptable standards, you need to set benchmarks against which to measure your data.

Benchmarks depend on an array of factors; take them all into account so you can be confident that you’re comparing apples to apples.

These factors include industry types, email list segmentation, types of emails, numbers of links in the email, and more.

This means that what constitutes an acceptable CTOR rate can vary widely from transactional campaigns with a single CTA to triggered promotional campaigns.

As such, it makes sense to benchmark your own campaigns by individual type over time.

For instance, establishing CTORs for newsletters, transactional emails, triggered campaigns, and promotional emails allows you the opportunity to identify specific areas for improvement. Then you can track your performance over time based on individual creative efforts in particular emails and/or campaigns.

Every metric provides a piece of the puzzle and a glimpse at the big picture, but no metric should be viewed as a stand alone, definitive illustration of your marketing efforts.

Indeed, CTOR, open rate, deliverability, click-through statistics, conversions, and unsubscribe rates should be married to data that expresses return on investment, revenue per email breakdowns, and average order values to arrive at a comprehensive email analysis over time.

Take Control of Your Email Marketing Campaigns

Email marketing still offers huge potential returns for companies who do it right, but without useful data success (and improvement) will be impossible to track.

While merely releasing a blast of emails out to your subscription list and hoping for the best might save you time, utilizing proper metrics to assess the campaign’s performance provides the foundation for ongoing improvement.

At the heart of that analysis is understanding the important role that CTOR can play.

CTOR is sometimes referred to as the “effective rate” of an email, so if you are worried that your current creative focus is missing the mark, then you definitely need to include this metric to get the best possible analytical results.

Successful email marketing campaigns are more of a marathon than a sprint. That means you should be constantly fine-tuning your message to elicit a more engaged response, and CTOR rates are instrumental in judging and making course corrections in that process.

When added to the metrics you’re probably already using, CTOR data will give you a richer appreciation for what excites your email client base. Tapping into this excitement is what encourages your would-be customer to engage more deeply in your email marketing efforts.

Other Articles You Might Be Interested In:


get the agile marketing styles ebook

Andrea Fryrear
About the Author:

Andrea Fryrear

Andrea loves to dissect marketing buzzwords and fads looking for the pearls of wisdom at their cores. Her favorite topic is agile marketing, which she believes holds the key to a more fulfilling (and less stressful) marketing career for individuals and a more powerful marketing department for business. When not scrutinizing the latest agile methodologies, Andrea can be found on the volleyball court, at the park with her two delightful kids, or baking “calorie-free” cookies. Connect with her on Twitter @AndreaFryrear, or on LinkedIn.




Leave a Comment