Marketers use a wide array of email marketing metrics to track success. While each metric is useful individually, they provide much more insight when viewed together. Choosing the right set of email marketing KPIs offers a more holistic and nuanced view of campaign success so you can improve future ones.

Which email engagement metrics are suitable for your campaign depends on your goals, but some KPIs, such as open and conversion rates, are beneficial for most. Read on to discover nine data points every marketer ought to track to craft more effective campaigns.

Why you should track email marketing metrics

Email marketing metrics indicate whether your email campaigns engage leads and current customers. You glean valuable insights from them that help you adapt your current and future email lead generation campaigns.

Great email campaign services like Mailchimp and HubSpot automatically track popular email marketing analytics, such as open rate and unsubscribes, so using one is in your best interest. The more metrics you track, the more capable you are of measuring engagement, brand awareness, and sales attributions.

Knowing your email metrics and observing their interconnectivity is the only way to fully understand what is and isn’t working. For example:

• If your open rate is low, your emails might be getting reported as spam.
• If your click-through rate (CTR) is low on specific devices, your emails may not load well on those devices.
• If your open rate is high but your CTR is low, your subject lines might be effective, but the body text call-to-action (CTA) buttons aren’t.

9 email marketing KPIs you should track

Most email marketing services provide a detailed dashboard for your email marketing analytics filled with valuable data points. Here’s a list of the best email marketing KPIs you should consider first.

1. Click-through rate

Your CTR is arguably the best indicator of your email campaign’s overall strength. It measures how often subscribers follow a link from your email, meaning they read at least some of it and were interested enough to learn more.

‍Pro tip: Often, a well-placed link in the text of your email can outdo an ostentatious call-to-action button. Experiment with different layouts and techniques to discover what your audience responds to.

2. Conversion rate

In email marketing, your conversion rate measures how often viewers follow a link from your email and then go on to complete some action, such as making a purchase or filling out a form. This is an indicator of their readiness for a bounce-back campaign, where you bounce this new customer back to make another purchase.

‍Pro tip: Discount codes and limited-time offers make for high conversion rates, but they're easy to overdo (meaning recipients might get frustrated by all the emails). Whatever you try, ensure your links lead the reader to a place where there are the fewest steps between them and the desired action.

3. Share rate

Your share rate measures how often readers click a “Share” button in your email. Shares are beneficial because they extend your reach organically across other platforms. If you’re getting significant shares (5%+), identify and expand on what you did right.

‍Pro tip: To increase your share rate, style your emails to resemble the social media platform you're trying to get shared on. That way, the right platform is front of mind, and you stress your desired action. 

4. Domain-specific metrics

It’s crucial to compare your metrics across all domains, such as Gmail, Outlook, and Yahoo. If any domains have an unusually low CTR or an exceptionally high rate of spam reports, you may have a formatting problem. Check your designs to make sure they load correctly across platforms.

‍Pro tip: Email delivery services offer testing environments where you can simulate devices or domains. However, they aren’t perfect. For complete confidence, set up test accounts on all the domains you send emails to and add their addresses to your email list. When you send an email campaign, check how those emails appear in your test account inboxes.

5. Reported as spam

If enough readers report your emails as spam, domains automatically mark them as spam. And if this practice continues, they might reject your emails altogether. That’s why you should send emails in small batches to warm up your email domain at the start of your campaign. After it’s warmed up, emails are less likely to get marked as spam.

‍Pro tip: Ensure your emails contain well-written copy and professional-looking formatting. Avoid trotting out overused buzzwords like “attention” and “buy now,” and refrain from using caps lock or several emojis in your subject line.

6. Email open rate

This measures the number of people who opened your email. Some email service providers offer privacy settings that throw off this metric considerably, but email open rate can still be useful to monitor it over time to see how it’s trending.

‍Pro tip: The best way to improve your open rate is to develop a consistent, recognizable brand voice. Then, write your subject lines in a way that resonates with that voice. That way, loyal customers will know your emails aren’t spam.

7. Unsubscribe rate

Your unsubscribe rate is a tricky metric. On the one hand, you want to reach as many readers as possible. On the other hand, you want recipients who actually want your emails. When someone unsubscribes, they’re telling you they don’t want your content. They’re removing themselves from the pool, which prevents them from dragging down your metrics.

‍Pro tips: A healthy unsubscribe rate (~3%) can be an excellent opportunity to engage in real-time marketing. Make a social media post or send an email asking people why they chose to unsubscribe. You’ll gain new insights, and you might re-engage some folks.

8. Device statistics

As you peruse your analytics dashboard, review the device-specific breakdowns to determine which ones your emails are most successful on. This could reveal additional insights about other metrics.

For example, you might discover that mobile users are more likely to convert than desktop users. If that's the case, investigate your desktop user experience to learn why it's less effective than mobile.

‍Pro tip: Always test your emails on multiple devices. Your emails’ deliverability depends on rendering correctly on mobile and desktop devices. Domains will mark your emails as spam if they discover that they don’t render correctly, which could harm the deliverability of future email campaigns.

9. Bounce rate

Your bounce rate captures the number of times your emails failed to reach an address. This could indicate errors in your list of subscribers or outright fake email addresses. To reduce this rate, audit your subscriber list to remove entries that bounce. Many service providers have a feature that does this automatically. 

‍Pro tip: To keep your bounce rate low, require subscribers to verify their email during signup.

How to choose KPIs to track

There isn't one “best” set of KPIs for measuring email marketing campaign success — the right ones depend on your goals. And while every campaign benefits from high click-through and conversion rates, don't let that distract you from the essential gains indicated in other analytics, such as your share and unsubscribe rates.

For example, if you want to create brand awareness for a new startup, your primary KPI would be the number of leads generated. That means you want a high email open rate and CTR, but you should also monitor secondary metrics like your unsubscribe, spam, and bounce rates, as these are your greatest obstacles to gaining momentum with readers. 

You can translate these goals into the following thresholds:

• Unsubscribe and spam: <0.1%
• Bounce rate: <3%
• Email open rate: 35%
• CTR: 3%

The best tools for customer engagement

Tracking marketing metrics is an essential component of a broader, more holistic marketing strategy. To optimize that plan, you’ll need a suite of tools that allow you to change your tactics as data comes in. 

Webflow brings your entire team together — from developers and designers to marketers and content editors — to execute and monitor marketing initiatives. Webflow supports integrations with analytic tools that help you stay on top of your data.