Clicks and/or click-to-opens

3 minute read

Analysing which links in a campaign are clicked is a very common, if fairly elementary, way of measuring campaign engagement. Of course not all campaigns have additional linked content, but many do, and a subscriber who goes on to investigate further content is a sure sign of interest.


Clicks (sometimes referred to as click-through rate or CTR) and clicks-to-opens (sometimes referred to click-to-open rate or CTO) are two similar measures which are easily confused.

Firstly, to define the two measures.

Click-through rate is defined as the number of unique clicks divided by the total of emails delivered. You may also see this referred to as the click-to-deliver rate.

Click-to-open rate is the proportion of opened emails that had a link clicked. It is defined as the number of unique clicks divided by the number of opens. Both results are expressed as a percentage.

Assuming a successful open, a click is recorded when a subscriber goes on to click one or more links in the campaign. It could be text or an image, anything with an embedded link reference. A point to note – I’ve come across different variations so check how ‘your’ clicks are defined. We always record unique clicks (multiple clicks by the same person within a campaign are not recounted) as we feel this gives a more realistic measure of engagement.

Since it requires both a successful open and a conscious completion action by the recipient click-through rate is generally a better measure of campaign engagement than open rate. It helps you to differentiate the motivation for opening your campaign and for subsequent interaction with your content. However we’d also recommend that you review your click-through results in relation to your click-to-open rate and ultimately to any specific objectives.

It’s true that both measures allow a measure of interest in the content. We use ‘X to Open’ (where X = Click or Unsubscribe) figures as ways to compare the performance of the actual campaign content because these look at what happens after the first objective of someone actually opening the campaign has been achieved. Because it relates clicks to the number of opens rather than the number of delivered click-to-opens also allows you to better review the relative performance of different campaigns.

What should you expect?

We’ve been tracking click and click-to-open rates in our annual Benchmark reports since 2009. Averaged across all of the 25 industry sectors that we classify these have varied between 2.95-3.56% and 10.79-18.07% respectively.

Watch this space for the latest update – our 2016 Benchmark report will be published very soon.

Clicks history CTO history

By the way – adding lots of links into a campaign doesn’t necessarily make it more likely that your readers will interact in the desired way. It depends on your objective but sometimes it’s better to have a single or possibly just a few clearly defined ‘click’ objectives.