Essential Email Marketing Metrics and How to Optimize and Improve Them

Imagine sending out an email campaign but not quite knowing what success looks like. Why are you sending this email in the first place? You know certain metrics are important, but which data is key to understanding whether your email campaign is truly successful? Being data-driven in email marketing is the difference between an optimized marketing machine and simply sending out so-called “email blasts.” We want to move away from the days of batch-and-blast emails and toward a data-driven approach. To do that, we need to think deeply about the email metrics and analytics that drive our campaigns.

In this post, we’re going to take a closer look at the email marketing metrics you should be tracking and how to use those metrics to build a better marketing strategy. By the end, you’ll know which metrics to monitor, how to monitor them, and what to do with them to turn data into actionable insights.

Email Deliverability Metrics

Let’s start with the first leg of the journey for your email message: delivery metrics. Delivery metrics lay the foundation for a data-driven email strategy. Before you can actually engage your audience, you need to make sure that your emails are reaching them. Metrics like delivery rate, bounce rate, and spam complaint rate all play an important role in determining how well your emails are being delivered.

Think of email communications and delivery metrics as invitations to a party—you want to ensure the invites actually make it to your guests' mailboxes. If they don’t arrive on time or end up in the wrong mailbox, your guests won’t be showing up, and that would be a disappointment for everyone. Delivery rate is like getting past the front door and ensuring that your message is at least in a place where people can see it.

Three metrics to consider here:

• Delivery Rate: This is the percentage of emails successfully delivered to recipients' inboxes out of the total sent. It indicates your email’s ability to reach an inbox without bouncing.
• Bounce Rate: This is the percentage of emails that couldn’t be delivered. Bounces fall into two categories:
  • Soft Bounces: These are temporary issues, like a full inbox.
  • Hard Bounces: These are more permanent issues, such as an invalid email address.
• Spam Complaint Rate: This is the percentage of recipients who mark your email as spam. This metric is increasingly important, especially with new guidelines from email clients like Gmail, where a high complaint rate can harm your sender reputation and reduce future email deliverability.

Email Engagement Metrics

Continuing with the analogy, if your email is a dinner invite, then once it’s delivered to your audience, you’ll want to ensure they engage with it. You want them to get all the necessary details, capture their attention, and spark some action. Now that the email has made it to the inbox, we use engagement metrics to gauge just how engaging it really is. This is where classic email marketing metrics like open rates, click-through rates, and conversions become critical.

Once the email is in the inbox, we want people to actually interact with it. This is where a lot of marketers focus on A/B testing, design improvements, and fine-tuning call-to-action (CTA) placement to make sure the email is enticing enough for recipients to open. Here are the key metrics to focus on:

• Open Rate: This is the percentage of recipients who open the email, reflecting their initial interest. It shows whether the subject line and preview text are compelling enough to capture attention. With Knak’s AI features, you even have the option to let AI craft these for you if you’re struggling to come up with a catchy opener.
• Click-Through Rate (CTR): This is the percentage of recipients who click on at least one link within the email. CTR measures the email's ability to prompt recipients to explore further—whether it’s engaging with your brand, visiting a landing page, or seeking additional information.
• Click-to-Open Rate (CTOR): This is the percentage of recipients who click a link after opening the email. CTOR highlights the relevance and general effectiveness of the email once it’s been opened. Are people opening the email and then being enticed to click at a high enough percentage?
• Conversion Rate: This is the percentage of recipients who complete the desired action, such as making a purchase or signing up for a webinar, based on the email’s content and CTAs. It helps you evaluate how effective the email is at driving the desired action.

Together, these metrics help you understand how well your email is performing in terms of engagement and where there may be opportunities for optimization.

Email List Health Metrics

Most of us in email marketing want to ensure that we build healthy subscriber lists that grow over time and keep our subscribers happy and engaged with our content. If our email is a dinner invite, even if people don’t accept it—meaning they don’t convert or complete the desired action—we still want them to think of us in a friendly way, open future invites, and maybe even share those invites with friends. The key here with email marketing list health metrics is to maintain a strong foundation, which supports an effective email marketing strategy.

The total number of people on your subscriber list is a great indicator of your marketing’s reach and effectiveness. Here are some metrics to monitor for list health:

• List Growth Rate: This is the rate at which your email list grows over time, calculated by adding new subscribers and subtracting unsubscribes and bounces. It reflects your ability to attract new audience members and retain existing ones. Your list can grow through various methods, such as subscription forms on your website or other lead-generation mechanisms.
• Unsubscribe Rate: This is the percentage of recipients who opt out of receiving future emails. A high unsubscribe rate can signal issues with email relevance or frequency and may indicate a need for refinements to your content or segmentation strategy. While some unsubscribes are natural, it’s important to monitor this metric for any unnatural spikes.
• Email Sharing/Forwarding Rate: This is the percentage of recipients who share or forward your email content to others. It’s a valuable metric that shows how engaging and valuable recipients find your content. If they’re motivated to pass it along to friends or colleagues, it’s a sign that your content is resonating well.

Email ROI Metrics

Email marketing return on investment (ROI) metrics are critical for understanding the business impact of your email campaigns. Let’s say your dinner invite includes a paid portion, so guests who attend will pay for their plates. In this case, you’d be able to assess the general ROI of each invite based on how many people show up and pay. This goes beyond clicks and opens—it's about generating tangible results. The effort you put into email marketing should create value for your business, and that’s ultimately what marketing is all about.

It’s essential to compare the revenue gained from email campaigns to the cost of running them and, if possible, calculate the revenue generated per email. Here are a few key metrics to consider:

• Return on Investment (ROI): This metric measures the overall financial return of an email campaign. It’s calculated by subtracting the campaign cost from the revenue generated, then dividing by the campaign cost. ROI indicates the profitability of your email efforts.
• Revenue per Email: This reflects the average revenue generated per email sent, helping you understand the monetary impact of each email on your business.

Other relevant metrics include:

• Lead Score Impact: This metric assesses how an email campaign influences lead scoring, indicating a prospect's level of interest or engagement. Higher lead scores suggest an increased likelihood of conversion, helping guide sales outreach efforts.
• Lifecycle Advancement Rate: This tracks the rate at which leads move from one stage of the customer life cycle to the next due to email engagement, such as progressing from a marketing-qualified lead (MQL) to a sales-qualified lead (SQL). It’s a useful metric for evaluating how effective your emails are at advancing prospects through the life cycle.
• Pipeline Contribution: This measures the percentage of the sales pipeline influenced by email marketing campaigns, helping you tell an overall story about the impact of your email efforts on sales activities.

List of Email Marketing Metrics

Let's summarize the email marketing metrics we've discussed in this post.

Optimizing Email Marketing Metrics Through Email Design

When it comes to improving your email marketing metrics, the first place to look is your email design. There’s so much you can do within the design itself to optimize these metrics. Using insights from these metrics to inform design decisions can make a significant impact on your overall performance. Here are some essential design elements to consider:

Responsive Design

The vast majority of business users and consumers access emails on mobile devices or smaller screens. Ensuring your emails automatically adjust to different screen sizes improves readability, which can substantially boost open and click rates. Responsive design is non-negotiable in today’s digital landscape—you want every email to be accessible, regardless of the device it’s viewed on. By accommodating different devices, you’re removing barriers and ensuring a more enjoyable experience for your audience, which helps with overall engagement.

Responsive Design

The vast majority of business users and consumers access emails on mobile devices or smaller screens. Ensuring your emails automatically adjust to different screen sizes improves readability, which can substantially boost open and click rates. Responsive design is non-negotiable in today’s digital landscape—you want every email to be accessible, regardless of the device it’s viewed on. By accommodating different devices, you’re removing barriers and ensuring a more enjoyable experience for your audience, which helps with overall engagement.

Clear and Compelling Calls to Action

Strong buttons with clear, action-oriented text encourage clicks and can improve both your click-through and conversion rates. Use contrasting colors, large buttons, and concise text on your CTAs to make them stand out. Additionally, testing button placement and other design choices through A/B testing is essential. Placing CTAs above the fold is a smart move for visibility, ensuring that your audience sees them right away without needing to scroll. Effective CTA design guides readers to the action you want them to take, making it easy and intuitive to follow through.

Personalization

Segmentation and dynamic content allow you to personalize every aspect of your emails, from the subject line to the email body. Personalization can significantly improve open and click-through rates, making emails feel more relevant to each recipient. Instead of sending out a generic invitation, craft emails that speak directly to each user’s interests and needs. For example, personalize the message with the recipient’s name and highlight specific reasons they would be interested in what you’re offering. By tailoring your emails in this way, you show your audience that you understand and care about their unique preferences.

A/B Testing

Testing should be at the core of your email marketing strategy. Use A/B testing to experiment with variations in subject lines, images, colors, and CTAs to understand which design elements resonate best. Platforms like Knak make it easy to test different modules, segmentation strategies, dynamic content, and CTAs. With A/B testing, you can continually optimize your emails based on data and insights. By systematically testing each element, you can improve your email’s overall effectiveness and create content that better aligns with your audience’s preferences.

Optimize Preheader Text

Your preheader text acts as a secondary subject line in the email inbox, so it’s essential to make it count. A concise and compelling preheader that matches the subject line can create a sense of urgency or entice users to open the email, significantly boosting open rates. Think of it as a teaser that complements the subject line, providing a preview of what the email contains. Effective preheader text can enhance curiosity or drive urgency, both of which can increase the likelihood that the recipient will open the email.

Alt Text for Images

Including descriptive alt text for images is crucial for accessibility, ensuring that recipients can still understand your message even if images don’t load. Alt text communicates key information and is especially useful for those who rely on screen readers. It also helps reinforce your message visually, which can be especially important in cases where email clients block images by default. Well-written alt text provides context for the images, ensuring that all users, regardless of their email settings, can grasp the email’s core content.

Visual Hierarchy

Organizing your email’s text, images, and buttons in a logical way guides readers’ attention naturally from the header to the CTA. Establishing a clear visual hierarchy makes the email flow in a way that’s easy to follow, helping readers quickly find the most relevant information. This structure should prioritize key content and include strategically placed visual cues to keep readers engaged. Effective visual hierarchy doesn’t overwhelm the recipient; instead, it leads them smoothly from one section to the next, keeping the focus on the most critical points.

Brand Consistency

Consistency in branding across emails and web properties is critical for building recognition and trust. Use the same logos, colors, and typography that align with your other marketing materials, such as landing pages and social media profiles. This approach creates a seamless experience when your recipients engage with different brand touchpoints, enhancing authority and reliability. Additionally, brand consistency supports a cohesive journey for users who click through from an email to a landing page, reinforcing your brand’s identity at every step.

Preference Center

Including a preference center in your emails can help reduce unsubscribe rates by giving users control over the types of content they receive and the frequency of communication. Offering alternative options helps retain subscribers and keeps them engaged with your brand on their terms. Preference centers can include options for content categories, sending frequency, and other settings that make the user experience more customized. This way, instead of opting out entirely, recipients have the flexibility to adjust their subscription to better align with their interests.

The Role of No-Code Email Builders in Optimizing Email Metrics

The rise of no-code email builders like Knak has provided marketers with powerful tools to take control of the email creation and optimization process, eliminating the need for technical coding skills to produce responsive, visually compelling emails. If you put all of this together, the opportunity to optimize your email metrics through email design is greater than ever before. Now, marketers can focus on creativity, experimentation, and optimization—all without relying on developers.

It’s never been easier to create emails that look great on any device. It’s also never been easier to experiment with different design elements, layouts, and calls to action. No-code platforms like Knak empower you to test every aspect of your emails, from subject lines and preheaders to the entire layout and structure of the email itself. By developing A/B tests that range from small elements to full templates, you can discover what truly resonates with your audience.

The journey of optimizing your email metrics is iterative—a journey that unfolds over a series of campaigns, each building upon the insights and metrics gathered from the last. A data-driven approach to email marketing goes hand in hand with a design process that fosters creativity and allows you to experiment, all while staying true to your brand’s identity.

By focusing on the design aspect of email and putting that process in the hands of marketers, we now have the freedom to try new approaches and continuously optimize for the metrics that impact the bottom line. This alignment of data-driven insights with a flexible, creative design process has transformed email marketing, enabling us to connect with our audiences in a more engaging, measurable, and impactful way than ever before.