Open Reach Rate

By Jeanne Jennings

Apple’s Mail Privacy Protection Initiative which is included with iOS 15 and is expected sometime in the fall of 2021 will impact Open Rate, Click-to-Open Rate, Open Reach Rate and Render Rate for users reading mail on Apple Mail. The information here may change and we will update it when we know more. To learn more visit the Only Influencers Pixelgeddon Resources Page.

OpenReach Rates are between 0% and 100%; once you finish the equation, turn your answer to a percentage by multiplying by 100. Unlike Open Rate, which gauges performance on a single email message, OpenReach Rate shows you what unique percentage of your list opened at least one of a series of email messages.  

For instance, let’s say you sent a series of three email messages, and your unique open rates were 34.7%, 31.3%, and 29.7%. You would want to know whether:

1. Each of these people only opened one of these email messages, meaning that 95.7% of your list (the sum of the three unique open rates) opened at least one message.
2. The 31.3% and 29.7% of people who opened messages 2 and 3 were subsets of the 34.7% who opened message 1, meaning that only 34.7% of your list opened this series.
3. The truth lies somewhere in between. 

Reach Rate can tell you whether the answer is A, B, or C — and if it’s C, it can tell you exactly what percentage of your list opened at least an email message in this series. 

Calculating Open Reach Rates

I wish it were easier (I’m talking to you, ESPs), but the way to calculate reach rates is to consistently dedup those who opened your latest sends against those that opened the previous sends. 

Here’s an example: 

Now, you most likely have more than ten people on your email list. And maybe you have open rates of 40% on every send — or maybe you don’t. But you get the idea. Open reach only counts new openers – not people who have opened on previous emails in the series. 

Tips for Interpreting Open Reach Rates

Open Reach Rates should only be calculated when the same people are receiving each email in the series; you can’t calculate Open Reach when you send the first email to 1M people in group A and then the second email to group A plus another 500,000 from group B.

Open Reach is most valuable when you are looking to gauge the success of a series of related emails, not a group of unrelated messages. 

Open Reach is most often reported as a graph like the one below, in conjunction with Click Reach. 

Here is the data that led up to the graph above, counting only new, not repeat, openers in the click reach figure. 

See our other articles for examples of other metrics based on opens like Open Rate. 

Open Reach Rates show you how engaged the people on your list are. While Open Reach Rate isn’t the end goal, it’s a step toward the end goal — and by boosting your Open Reach Rate, you can often see a lift in Return-on-Investment (ROI), Revenue-per-Email (RPE), and other business metrics. 

Related Links

I wrote about Understanding and Leveraging the Power of Open and Click Reach Rates in Email Marketing for the Webbula Metrics Series in early 2021. 

Back in 2013, the DMA UK also published on the topic in Email Engagement: Often Talked About, Never Defined.