One of the reasons email is so powerful is that you receive instant feedback on your messages. Yet, even with institutions doing a high volume of email marketing, I still find a basic lack-of-understanding regarding what these metrics are and how they are calculated.  This post is intended to be a basic primer for that information. 


Unique versus Total Rates

For both opens and click throughs, it’s possible for an email service provider to calculate both unique and total numbers.  Here’s the difference: 

  • Unique opens/click throughs are the total number of your recipients who took that action.
  • Total opens/click throughs are the total number of times that action occurred. 

For example, say Johnny Jones got an email that you sent him and was so thrilled that he opened it and reread it five times.  This will count as one unique open, and five total opens.  This is an important distinction, since most of the rates we are going to talk about are typically calculated using the unique number.  If your email reports don’t specifically distinguish between the two rates, make sure you’ve worked with your provider so that you know what the numbers you are looking at mean.


Email Open Rates

What is it? 
Your open rate is the number of unique opens weighted against the total number of emails delivered.  You can calculate it using the following formula: 

Open rate=(number of unique opens / [emails sent - emails bounced]) X 100 = XX%

Most email service providers will do this work for you, so you don’t have to concentrate on the math.

How is it measured?
Open rates are typically measured in one of two ways:

  • In HTML emails, an invisible image is automatically inserted into the body of the email.  When the user opens the email, the image is loaded and counts as an open.  
  • If a user clicks on a link in your message (and you’re tracking click throughs), the ESP assumes that the user opened the email and counts it.

You can see that this way of measurement could be problematic - a lot of people don’t load images automatically when they open their email, which means that unless they click on a link in the message, it won’t be tracked.  Also, if your user receives a text email rather than the HTML version, the open won’t be tracked.  For these reasons, its helpful to consider open rates more art than science and just use them as a helpful guide to track your institutional trends.

One final note…
Just because a user has opened an email does not mean they have read it.  There’s no way to track that.


Email Click Through Rates (CTR)

What is it?
Anytime a user clicks on a link in your email, it counts as a click.  Simple enough, right?  Your CTR is calculated using the following formula: 

CTR = (number of unique clicks / [emails sent - emails bounced]) X 100 = XX%

Again, most ESPs will do this for you but ensuring that they are using the unique number versus the total number of clicks is key to getting an accurate statistic.

But not so fast…
It’s not the best idea in the world to track click throughs in text emails.  Here’s why: 

picture-24

Not very user friendly, right?  Since text email makes up such a small percentage of your recipients (I’ve never seen any stat higher than 2%), I usually choose to let go of that bit of tracking for the sake of having an enhanced user experience with the message.  Make sure to work with your ESP to disable click through tracking on the text versions of your emails, if that’s not a change you can make on your own.


Click-To-Open Rate (CTOR)

What is it?
This is a wonderful, magical statistic that most ESPs just don’t tell you about or calculate for you.  Which is a shame.  I think its a much more accurate indicator of how successful your email copy was in getting your users to take that ultimate call-to-action. 

Instead of weighing unique clicks against the total number of emails that were delivered, CTOR weights unique clicks against the unique number of emails that were opened: 

CTR = (number of unique clicks / number of unique opens) X 100 = XX%

I don’t think I’ve seen an ESP yet that will automatically calculate this statistic for you, so its time to break out the calculator!

Not without it’s problems…
As we discussed with the open rate, calculating the number of emails that were opened is just not an exact science so this rate can be prone to have a really inflated percentage.  As with most email metics, it’s a great thing to look at in context and could be a helpful tool in identifying trends over time.


Unsubscribe Rate

What is it? 
I think this one is pretty self-explanatory, but this is the percent of users who have elected to unsubscribe from future communications with you through this message.  Unsubscribe rates are typically pretty low, definitely less than 1%.  If you see a message with a rate that is significantly higher than that, step back and take a hard look at the message to try and suss out why it triggered a large number of unsubscribes.

Don’t make assumptions!
Don’t assume that because a user unsubscribes from your messages that they are no longer interested in your institution.  The only thing this lets us know about your users is that they don’t want to receive email communications from you any more.  Don’t make assumptions that this means they don’t want to receive other types of communications from you.


How can you use this information? 

  • Set benchmarks for your institution and track them over time.  Use these benchmarks to assess which emails are triggering results and which are floundering. 
  • Use it to plan your email strategy - try doing followups to users who didn’t open or click through on the original message.
  • Conduct A/B split tests, to see what tactics your users respond to and refine your email program.

Those are just a few ideas.  Regardless of what specifically you decide to do with this data, doing something is better than doing nothing.


Did I miss anything?   Leave a comment to ask any additional questions.

Like what you read here?  Subscribe to this blog through RSS or sign up to receive email updates when new content is posted.