Email marketers often obsess over two parallel metrics: open rate and clickthrough rate (CTR). Open rates presumably let 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?

Open, Clickthrough, Click-to-Open Rates: Defining Email Marketing Metrics

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.

Click-to-open rates, 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.
  • Clickthrough 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 Metrics and Best Practices

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 click-to-open rate lets you analyze, benchmark and diagnose design and content issues regardless of other messages’ open and clickthrough 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.

Email Marketing 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, 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.

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 in email marketing effectiveness.

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.

Andrea Fryrear is a marketing coach and trainer.

Learn more about Marigold Engage by Sailthru’s Email Marketing Automation platform and how it can help you improve click-to-open rates.