The Difference Between CTR and CTOR

The industry often relies on a click-through rate to measure the effectiveness of an email campaign. In talking to professionals even within the email industry however, I’m often surprised at how many people don’t understand the terms fully or use them incorrectly. Here I will overview the most common references.

Click Through Rate (CTR)

CTR is the measurement of the number of clicks on links within a given campaign divided by the number of recipients who were sent the campaign. Generally this is illustrated by a percentage. So, if you sent a campaign to 100,000 subscribers and record 1000 clicks then the CTR would be .01 or 1%. The problem is that while most in the industry refer to CTR as the core metric they tend not to disclose if the CTR is really the TCTR or the UCTR… which we will discuss next.

Total Click Through Rate (TCTR)

Within a specific campaign there may be multiple clicks for any given subscriber. If one subscriber clicks on links within the campaign more than once that would increase the TCTR as the TCTR is a measure of TOTAL clicks divided by subscribers. This happens more often than you think as a subscriber may click on the same link on multiple devices or may forward/share the link with other who also click on it. The TCTR is representative of the popularity of a campaign but it isn’t representative of the % of subscribers who engage.

Unique Click Through Rate (UCTR)

UCTR is a more representative number to reflect the number of subscribers who are engaging. It is calculated by looking at the total number of unique subscribers that clicked at least once on a link within the campaign and dividing that by the number of subscribers.

Click To Open Ratio (CTOR)

In this measurement we only want to measure the percentage of subscribers that OPENED the campaign that also clicked on a link. While CTR measurements take into account the effectiveness of both the subject line and the email copy, the CTOR tends to focus only on the email copy’s success in driving the user to click. This can be an effective number to look at as it removes factors that can diminish CTR like a recent successful opt-in campaign that has dramatically increased subscribers that may not be as prone to click as subscribers that have been on the list for a period of time.

The most common mistake I find in the industry is people calculating the CTR using CTOR numbers. Perhaps this is because they like the sounds of the higher percentage points… but that isn’t the correct use of the term.

To learn more about the metrics used by Interspire Email Marketer in the stats dashboard please refer to our previous article about understanding the IEM stats.