by Loren McDonald , Thursday, April 24, 2008
THE EMAIL OPEN RATE IS simply a tired, inaccurate and irrelevant metric that no longer measures what it was originally intended to. As a result, it gives you the wrong picture of your subscribers' interest in and involvement with your mailings. ("Engagement," if you want to use the buzzword).
Using the open rate to measure email marketing performance is akin to the music industry measuring sales based on the number of CDs sold. It just doesn't reflect how people buy music today.
How did we get here? The email open rate became a useful metric once HMTL messages became the primary email-message format, because it counted each time a tracking image loaded when the recipient opened an email.
This allowed marketers and publishers to measure how many people were "reading" their emails, distinct from those who also clicked on the email. Still, this metric was not a great measure because it didn't distinguish between someone who reads every word in a newsletter and someone who opens and then deletes immediately.
As soon as the major ISPs and email clients began disabling images by default, though, the open rate's accuracy and value plummeted. When combined with growing use of the preview pane, emailers got the double whammy of metrics mush.
Various studies (including my own from a few years ago) support that both consumers and business users of email view from a quarter to a half of their emails in a preview pane and 50% to 60% percent block images by default.
Now, add text emails to the mix. Someone, please, tell me how you can view open rates as an accurate and meaningful measure of anything other than the percentage of your HTML emails where images rendered?
Here are some real-world examples of the inaccuracies and inconsistencies of email opens: