You may have heard about the change in the way Gmail displays images in its emails.

Here’s a refresher…

Normally, every time a subscriber opens one of your marketing emails, the images are downloaded to their device — sending a signal to us here at Constant Contact that we register in your open rates report.

Now, Google is “caching,” or locally storing, images on its own servers to speed up the amount of time it takes to download them.

So how will this impact your open rates?

We’ve tested our systems, and Constant Contact continues to accurately track your unique open rates exactly as it always has.

Where you may see a difference is within your “All Opens” reports. Since Gmail is caching the images on its own servers, a signal will only be sent to us at Constant Contact the first time the email is opened (or if the email is opened after Gmail has cleared its cache).

Essentially, this means that every individual instance of a subscriber with a Gmail address opening your email may not be reflected in your Constant Contact “All Opens” reports. Other email service providers are also reporting similar findings.

Here’s an example of how this works…

One of your subscribers with a Gmail address opens your email. Gmail downloads the images to its servers and it registers in your Constant Contact report as a unique open. Later that day, the same subscriber opens your email three more times. You will not see a record of three instances in your
“All Opens” reports because Gmail is showing its user the locally stored cached version of the image.

Will your “Unique Opens” be more accurate than ever before?

In addition cached images, Gmail has also begun to roll out a change for its users that will display images by default. This means that email marketers aren’t reliant on Gmail users clicking on “Display images below” in order to register the open. These “always on” images could lead to more accurate and increased reporting of your unique open rates.

We’ll continue to monitor the impact of these changes for you.

If you’d like to learn more about how we test the impact of these changes, be sure to check out our post on the Tech blog about Gmail open tracking.