How Valid is an Email Open Rate?

Source: Kathleen Maher, Email Product Manager, V12 Group

Using the email open rate as a measurement of how well your campaign performed is not going to provide you with an accurate metric.

The reality is that there is no reliable method for determining how many people physically looked at your email. Email opens are anything but a precise measurement. Most marketers are use to the power of web analytic tools for measurement of behaviors on their websites – unfortunately, email measurement tools are not in par for comparison.

There are so many inaccuracies and inconsistencies of email opens; from reporting system to reporting system, how default settings are set, how and on what the email is being viewed, just to name a few.

But, don’t totally discard the open rate. The email open report can be used to spot major problems in delivery (if not a single AOL user opened your last newsletter, you know you have a problem.) It is good to use as a broad check on the healthiness of the list where you’re watching trends over time. Plus, if you’re running subject line tests with an A/B split, a dramatic difference can be quite useful.

Here are some real-world examples of the inaccuracies and inconsistencies of email opens:

· The email is “opened” (launched), but images are blocked: not counted as an open

· The email is not opened (launched), but images are enabled and is read in the preview pane: counted as an open

· The text version of a multi-part message is read on a BlackBerry. The HTML version (with images blocked) is later opened in Gmail (or other email service/client). The email has been opened and read twice — but zero opens are recorded.

· A text version is opened and read but not clicked: not counted as an open

· A text version is opened and read, but the user clicks a link: not counted as an open with some email software. Others assign an open because the email was clicked on, which assumes an open.

Conclusion: We recommend having a more tangible measurement in place for each campaigns like; a form to complete on a landing page that is only associated with the email, or redeem a coupon that is tied only to the email etc… But wait, this approach still will not provide accurate measurements because a recipient may forward the email onto several friends – and the friends engage which would throw off your reporting. The best approach is pay attention over time to how the list you are using is performing in general to see if there are any good averages you can use as baseline performance estimates.