Email Experience Council

The eec blog post introducing the new "render rate" (by the Measurement Accuracy Roundtable) has drawn dozens and dozens of comments to date – from supportive to some that question the value of the standardization initiative.

There were also a number of comments and questions that indicate many people still don't understand what the open rate does and doesn't measure and how open rates are actually tracked. This blog post will be the first of a series from various members of the Measurement Accuracy Roundtable that address the comments and questions posted on the blog.

Before diving into a detailed explanation of how the open rate works and what it does and doesn't measure, I wanted to remind everyone of the core objective and purpose of this initiative.

The Measurement Accuracy Roundtable was formed with two primary purposes:
1) To ensure that email industry metrics that were widely adopted accurately measured what they were designed to measure;
and
2) That the metric was measured consistently by vendors and marketers. The intent was not to eliminate metrics or pose our opinion or preferences on email marketers.

With that background and reminder, let's dive into the basics of the open rate, which hopefully conveys why the eec took up the initiative to standardize this popular email metric…

How open rates are measured: Your email technology automatically inserts html code that references an invisible (often referred to as a "clear" or "1×1″) tracking image in your email, usually at the bottom of the email.

Like the other images in your HTML emails, they are actually hosted on a server, not embedded within the email. When a recipient opens the email, and images are not blocked, the image is called/pulled into the html message from the hosting server. As the image is pulled into the message, it is appended with a unique identifier that is associated to the receiving email address. That rendering of an image associated to an email address has been commonly referred to as an "open." Now, it gets more complicated.

When an "open" is counted: With the above definition in place, let's look at the scenarios in which an open is counted or reported:

Images are not blocked when the recipient fully "launches" or opens the email.

Images are not blocked when the recipient views the email in a preview pane (a feature on an increasing number of email clients and services).

A recipient scrolls through the inbox slowly enough to allow the tracking image to load, even though the email was not actually viewed in full or in the preview pane.

A recipient clicks on a link in a text email. This particular email service provider or software counts the clicked link as an open. Even though there is no way to track whether the text message was opened (because it has no tracking image), we assume the recipient had to open the message (or view in preview pane) to view the message or click the link. Note: In this example the email tracking software would report one and open and one click.

A recipient clicks on a link in an HTML email that is fully opened, but images are blocked or disabled. The text-email logic applies here.

A recipient clicks on a link in an HTML email viewed in a preview page, but images are blocked or disabled. The text-email logic applies here, too.

A recipient views an HTML email on an iPhone, iTouch or other mobile device that automatically renders HTML emails with images enabled.

A recipient clicks on a link on a text or HTML email on a mobile device that does not render images. The text-email logic applies here.

When an "open" is NOT counted: OK, with me so far? Now, it gets even more confusing. Here are the scenarios when an open is NOT counted or reported:

Images are blocked when the recipient fully "launches" or opens the email.

Images are blocked when the recipient views the email in a preview pane (a feature on an increasing number of email clients and services).

A recipient scrolls through the inbox so fast that the tracking image doesn't have time to load.

A recipient clicks on a link in a text email. This particular email service provider or software does NOT count the clicked link as an open. In this case the rationale is that although an open can be inferred, it was not actually captured. Thus, the metric is kept "pure" and the open not counted.

A recipient clicks on a link in an HTML email that is fully opened, but images are blocked or disabled. The same text-email logic from the previous example applies here.

A recipient clicks on a link in an HTML email that is viewed in a preview page, but images are blocked or disabled. Again, the text-email logic applies.

A recipient clicks on a link on a text or HTML email on a mobile device that does not render images. The text-email logic applies here, too; thus, no open is tracked. The same text-email logic applies.

The HTML or text version is read on a BlackBerry or similar mobile device that does not render images.

An HTML email is viewed on a Blackberry (as above) and is later opened in Gmail (or other email service/client) with images blocked. The email has been opened and read twice, but no open has been counted.

I could probably come up with more scenarios that show how inconsistently an open is or isn't counted or reported, but you should have the gist by this point.

My fellow Measurement Accuracy Roundtable members will contribute a follow-on series of posts to further explain our rationale for the proposed render rate.

In the meantime, if anyone still doesn't understand how opens are tracked and reported, please post your question in the comments, and I'll give it another shot.

Lastly, I'd like to personally, and on behalf of the entire Measurement Accuracy Roundtable, thank everyone for their feedback and comments posted on the eec blog. Are you really passionate about this and other email measurement topics? Join the eec and our Roundtable!

- Loren McDonald, Silverpop
Co-Chair of the Measurement Accuracy Roundtable