Email Marketing Metrics That Matter Beyond Opens

Open rates used to be the default way to measure engagement. Apple's Mail Privacy Protection made them unreliable for a large share of most lists.¹ What replaces them is not a single number. Measuring email marketing beyond opens takes seven metrics, and they fall into three groups: what subscribers do, whether the list is healthy, and whether people want the mail.

Conversions and clicks show what subscribers actually do

Conversion rate is the one to track if you track nothing else. It measures the share of recipients who take the action you wanted after clicking, whether that is a purchase, a trial signup, or a white paper download, and it is the closest email gets to measuring business results directly. When it lags, look at the landing page as hard as you look at the email.

Click-through rate needs context to mean anything. A high rate is generally good, but look at where the links sit, whether they match what the reader cares about and what the message promised, and whether the destination delivers. Irrelevant links can still get clicks that never convert, and a link that baits and switches gets a click once.

Beyond the click itself, watch what subscribers do next. Website visits that start from email show deeper engagement than a click that bounces. Knowing which email clients your subscribers use won't tell you much about engagement, but it tells you where your design has to render correctly.

List growth, unsubscribes, and complaints show whether the list is healthy

List growth rate shows whether your acquisition is working. A flat or shrinking list is a reason to look at your signup forms, your offers, and your landing pages.

Unsubscribes are inevitable, and a consistently high unsubscribe rate is a symptom. The usual causes are content that doesn't match what subscribers signed up for, a sending frequency that wears people out, and messages that never make clear why they're worth reading. Look at the timing and content of the sends that produce the most unsubscribes.

Spam complaints matter most of all, because they feed directly into your sender reputation and from there into whether your mail reaches the inbox. Keep the rate low by mailing only people who opted in, making it easy to unsubscribe so nobody has to reach for the spam button, and removing inactive and invalid addresses.

Forwarding shows that people value the mail

When subscribers forward your mail or share it, they are telling you the content was worth passing along. Track forwarding and sharing to see which messages earn that, and make forwarding easy.

None of these metrics is useful as a one-time reading. Each is worth watching over time, and the program that improves is the one that changes something every time a trend moves in the wrong direction.