Engagement Metrics: Listen for the Sound of Customers Leaving

3. Read rate: This is the easy one. No matter what else you want from your messages, people should read them. A decline in your read rate is the quickest, most obvious indication that subscriber engagement is falling off. It’s the first sign that something is wrong. Instead of letting these subscribers fade away or, worse, end your relationship with a complaint, target them with a reactivation campaign as though they’ve stopped engaging altogether. Then watch read rates to see what changes they respond to. Also, keep in mind that you’re not the only one watching read rates to gauge the health of this relationship. Mailbox providers are using exactly this metric to see how you engage with readers.

These metrics can help you identify and solve a real problem before it impacts the health of your customer relationships. While testing email optimization tactics can help you find the right approach to reactivating subscribers, there’s one more area to explore when you’re diagnosing flagging engagement: rendering. Declines in any of these metrics may be related to erosion in your user experience as messages fail to render properly in changing email clients and increasingly used mobile devices. Identifying (and fixing) a rendering problem could save you from tinkering with a program that’s otherwise not broken.

Tom Sather is the senior director of research at Return Path, an email marketing solution that helps to improve deliverability and ROI.