Understanding Subscriber Engagement: Opens vs. Reads

Over the last few years, we’ve seen a shift in the email deliverability landscape. Major mailbox providers, like Gmail, have incorporated subscriber engagement factors into their filtering algorithms, making the sorting process much more dynamic (and challenging to navigate). While retailers have been closely watching subscriber engagement as a key success metric for many years, it’s important to note that mailbox providers have a different vantage point. That difference between a retailer’s definition of engagement and a mailbox provider’s could be the difference between getting your email campaigns delivered to the inbox or blocked.

Put simply, retailers view subscriber engagement through the lens of the purchase process, whereas mailbox providers view subscriber engagement through the lens of the inbox environment. This naturally creates a friction point, as “engagement” could include a variety of actions. For the purposes of this article, let’s compare and contrast opens and reads as a measure of readership.

Retailers Typically Measure Opens

When measuring the success of an email campaign, opens and related metrics (e.g., open rate, click-to-open rate, etc.) are the benchmarks commonly measured by retailers. Opens are tracked by a 1x1 pixel embedded in the HTML by the email sending platform. Each time the pixel is fired, the images from the message are downloaded to be displayed and the sending platform counts an open. It's generally accepted that this method provides an accurate capture of views; recent research from the DMA found the average open rate to be 25.1 percent.

There are some blind spots when using opens to measure readership, however. Opens, often shown as “total opens” in reports, may overstate the actual number of views if a message is seen more than once or accessed on different devices by the same user. Some reporting systems offer “unique opens” as a more granular way to view the metric, which counts only one open per email address. For example, Cheetah Digital reported benchmarks in last year's third quarter to be 25.8 percent total open rate and 17.2 percent unique open rate, so the variance can be quite large.

Additionally, because images must be rendered for an open to be counted, text-only, some mobile environments, and inboxes that don’t automatically download images (due to high security settings, for example) could be excluded from the opens calculation. With the prevalence of mobile, this can be a risk factor causing performance reporting to be inaccurate.

Mailbox Providers Measure Reads

When evaluating whether a subscriber is interacting with a message or sender, reads are commonly used as a benchmark by mailbox providers. A bolded sender name/subject line and new message count are common indicators used by mailbox providers and subscribers to identify unread messages within the inbox. Once the email has been selected, previewed, skimmed or similarly consumed, it becomes unbolded within the inbox, considered read, and removed from the new message count. Reads are tracked by the recipient’s inbox activity and based on a factor of dwell time. After the message is displayed for several seconds (regardless of images being rendered), the email is marked as “read” in the inbox. Recent research from Return Path found the average read rate to be 21.5 percent.

Like opens, there's a margin of error with reads. Because the read metric is based on inbox activity, there's a potential for discrepancies in reporting if subscribers are manually marking a message as read instead of actually spending time in the preview pane or consuming message content.

How Do We Bridge the Gap?

Both opens and reads are subject to the ever-changing wild card: the subscriber. Retailers and mailbox providers are striving to listen and respond to evolving digital consumption preferences. Even with these similarities, there are inherent differences between opens and reads, and neither tells a complete story on its own. Both opens and reads can be referenced as insightful directional indicators. Leveraged together, we can get a clearer view of how subscribers are choosing to consume messages from a brand.

All indications are that subscriber engagement is here to stay, becoming an increasingly important deliverability factor. Even more than understanding the difference, it’s important for retailers to begin measuring reads as well as opens. Mailbox providers are considering engagement in their filtering decisions, so marketers need to take control of their engagement metrics if they want to maximize inbox placement.

Bonnie Malone leads the consulting, client training, and knowledge and editorial organization of Return Path, an email data solutions provider.