Whenever you distribute emails to your subscribers, a fraction of them will get delivered, some recipients will cancel their subscription, some will open your email message and read it, and few will even take the next step and click on a link within it or take other action.
If you use an email delivery service like Aweber or Get Response or Imnica to handle your mailing list, then you will be able to access this data at the click of a link. Your report will include information such as the number of emails sent, bounces, opt-outs, opens and clicks.
Open rates are expressed in terms of a percentage of the total number of emails that were delivered to recipients. If you sent out 500 emails, and 5 of them bounced, then 495 got delivered. Of these, if 155 were opened, then your email open rate is 155/495 or 31.3%
But what exactly do we mean by “opening” email?
What Do You Mean By Email Open Rates?
Email open rates are measured by tracking systems implemented by the email service you use to distribute your messages. Typically what happens is that the service will automatically insert a small transparent GIF (an invisible “tracking image”) into your email message.
Now, when the service sends out your email and it arrives in your subscriber’s inbox, your reader will view it using an email client such as Outlook Express or Eudora or a Web-based email program. When the email message is opened, the tracking image is also displayed – even though it isn’t visible to the recipient.
The email client program sends a request to the email service for the image. This is monitored by the service, which now knows that the recipient has received the email and opened it. It records this “hit” as an “open”.
Every single message distributed by the email service will get its own unique tracking image, which allows the service to provide very granular reporting on which email addresses received and opened your message.
But does open rate mean your email got read?
How Emails Can Be Opened – But Remain Unread!
As we’ve seen just now, the moment your recipient’s email client triggers a request for the tracking pixel (image), the data is logged in your account as an “open”. But this does not mean your email was read, or even viewed by a person!
All that you can say from this information is that your email made its way into your subscriber’s inbox, and was acted upon by the email client in a way that triggered a pixel request.
It could simply mean that your subscriber has their ‘email preview’ preferences turned on. This is means whenever the SUBJECT line of your message is highlighted, the message shows up as a preview in a separate pane or tab – where it may or may not be viewed. Your subscriber may just be manually scrolling down a list of emails, and hitting DELETE after glancing at the headline!
Yet your email service will record this as an “open”.
And then, paradoxically enough, we have the reverse!
Your Emails May Be Read – But Not Show As Opened
Bizarre as it sounds, this happens because your email service can only track a message as opened if it receives a request for the tracking pixel.
Because the code for the tracking pixel image is in HTML code, this will only apply to emails sent and received in HTML format. If your email is viewed on a client program set to only display text versions, such as the default setting is on many mobile devices, the subscriber’s machine may not request the image at all – even though the recipient reads your email, and maybe even takes action based on it.
Many email programs are set to not display tracking images by default. This means the email message you sent is shown on the recipient’s screen – but your tracking pixel is not loaded, which means your email service will not count it as an “open”.
How Email Open Rates Are Calculated
We’ve looked at potential errors in how email opens are counted. Things get murkier when we talk about open rates – because these are presented as a percentage, and knowing exactly what’s being measured matters.
Some services report email open rates as a percentage of all emails that were successfully delivered to recipients. But some report it as a fraction of the total number of emails sent!
Now, if you have a significant “bounce” rate which affects the number of emails you were able to deliver, your email open rates will be further skewed by what metric is used by your service.
And that’s not all.
Some services count unique opens. So if a recipient opens and reads the same message repeatedly, it is only counted as one open. But others may count each incident as an “open”, misleading email marketers like you to incorrect conclusions.
As all this information shows, email open rates aren’t simplistic or very accurate. They are indicative metrics that give you a fair overview of the efficacy of your email marketing. We will see how exactly you can analyze email open rates to derive useful information about your email marketing efforts in another article.
About the Author:
Dr.Mani is a heart surgeon, Internet infopreneur and social entrepreneur. This article is one of his 4-part series on email marketing. You can read the others that explore email open rates in greater detail on his infopreneur blog.