12 Must-Follow Email Marketing KPIs for Measuring Your Campaigns’ Success 

Let’s face it: Email marketing may not be the shiniest, newest object in the digital marketing world. In fact, it’s been around for more than a quarter-century — and depending on who you ask, it’s arguably even older than the internet itself. But rest assured that, despite its age, email marketing isn’t going anywhere anytime soon, or even slowing down … and for good reason.

While email may be an ages-old marketing tactic (especially by digital marketing standards), it’s tried and true. And perhaps more importantly, it’s still highly effective, easily accessible, and extremely cost-efficient. 

Consider these powerful email marketing statistics:

• With nearly 4.5 billion email users worldwide, the targeted consumer audience for your client or brand is enormous.

• Spotlighting the tactic’s popularity and accessibility, more than 80% of all companies — and nearly 65% of small businesses — include email as part of their marketing strategy.

• Half of surveyed marketers say email is the most effective of the marketing channels they employ.

• And perhaps most compelling, the average ROI on email marketing is an astounding $36 for every $1 spent.

What are the best email marketing KPIs for measuring campaign success?

As the stats above demonstrate email marketing is still a worthwhile pursuit for any business or brand looking to grow their business. As a matter of fact, even decades after the first marketing-oriented email was fired off, the tactic remains among the most powerful in the modern marketer’s arsenal. 

For email marketing to reach its full potential, brands and marketers must understand how to measure email marketing success, which can enable them to fine-tune their strategies and foster engagement, higher conversions, and increased campaign success.

So, once you’ve launched an email marketing campaign, what are the best ways to measure its performance? First, you’ll need to measure results by the industry standards of what category your brand is in. Check out Mailchimp’s benchmarks resource as an example. By closely monitoring and analyzing the email marketing KPIs, your brand can make the data-driven decisions needed to optimize your email campaigns and better achieve your business goals:

1. Delivery rate

Delivery rate refers to the percentage of emails out of the total number of emails sent, that are successfully delivered to recipients’ inboxes. A high delivery rate indicates that your carefully crafted messages are reaching their intended audience, while a low delivery rate could point to potential issues that need to be addressed.

Understanding delivery rates can help your brand identify and resolve problems such as invalid email addresses, spam issues, and poor sender reputation. If a significant portion of your emails fails to be delivered it only wastes resources but also hampers the effectiveness of your campaigns. But by regularly monitoring delivery rates, your brand can maintain a clean and updated email list, enhance sender reputation, and improve overall email deliverability.

Measuring delivery rates can also help your brand gain insights into the health of its email marketing infrastructure by providing a clear picture of how well your emails are being received by email service providers and whether your messages are regularly being flagged as spam.

2. Open rate

Open rate is the percentage of recipients who open your email out of the total number of emails sent. This metric serves as an indicator of how compelling your subject lines and sender names are, as these are the first elements recipients see in their inboxes.

A high open rate suggests that your subject lines are effective in capturing the attention and curiosity of your audience, prompting them to open your emails. Conversely, a low open rate can signal that your subject lines are failing to resonate with your audience, your time to send might not work for your audience, or your emails are not making it past spam filters.

Furthermore, tracking open rates can provide valuable insights into your audience engagement and preferences. It can help your brand understand which topics or offers generate the most interest, allowing for more targeted and relevant content in future campaigns. While open rates alone do not guarantee conversions, they are a crucial first step in the customer journey, setting the stage for further interaction and engagement.

3. Click-through rate

Click-through rate (CTR) measures the percentage of recipients who clicked on one or more links within your email out of those who opened it. This metric provides a clear indication of how well your email content motivates recipients to take a proposed action, whether it’s visiting a landing page, signing up for an event, or making a purchase.

A high CTR signifies that your email content is relevant, engaging and compelling enough to drive recipients to click through to your website or landing page. It reflects the quality of your calls-to-action (CTAs), the appeal of your offers, and the overall alignment of your content with the interests and needs of your audience. On the other hand, a low CTR can indicate that your email content, design, or CTAs are not resonating with your audience, requiring adjustments to improve engagement.

By monitoring and analyzing CTR, your brand can gain valuable insights into what types of content and offers generate the most interest and action from your audience. This information can inform future email campaigns, allowing for more targeted and effective messaging. Additionally, CTR can help identify potential issues with email design, such as unclear CTAs or poor layout that may hinder recipient engagement.

4. Clicks per link

This metric tracks the number of times each link in your email is clicked, providing a detailed understanding of which elements are driving engagement. Unlike overall click-through rates, which give a broad sense of interaction, clicks per link allow your brand to pinpoint the exact components of your email that resonate most with your audience.

Tracking clicks per link offers several advantages. First, it helps identify the most and least popular content within your email, allowing you to tailor future messages to  meet your audience’s preferences. For instance, if a particular product link consistently receives high clicks, you can prioritize similar products or related content in subsequent emails. Conversely, links with low engagement can signal the need for improvement or removal, helping you ensure that your emails remain focused and effective.

Additionally, this metric can highlight the effectiveness of different CTA placements and designs. By analyzing which CTAs receive the most clicks, marketers can optimize their positioning, wording, and visual design to maximize engagement. This level of insight is invaluable for A/B testing various elements within your emails, helping you to refine your strategy based on actual user behavior.

Understanding clicks per link also provides deeper insights into the overall user journey. It reveals how recipients navigate through your content, which can inform broader marketing strategies beyond email. By seeing which links lead to further actions on your website, such as product purchases or form submissions, you can better understand the pathways that drive conversions.

5. Event lag

Event lag refers to the time delay between when an email is sent and when the recipient takes a specific action, such as opening the email, clicking a link, or completing a purchase. Analyzing this metric provides valuable insights into recipient behavior, helping marketers optimize their email timing and content for maximum effectiveness.

One of the primary benefits of tracking event lag is assessing the effectiveness of your email content. A shorter lag time between email delivery and recipient action indicates that your content and CTAs are immediately compelling. Conversely, a longer lag time may suggest that recipients need more time to consider your message or that the content lacks urgency. This insight can guide adjustments to your email content, such as emphasizing more immediate benefits or refining your CTAs to prompt quicker responses.

Further, measuring event lag can provide deeper insights into the customer journey. By tracking how quickly recipients move from opening an email to completing a desired action, marketers can identify delays in the decision-making process. This information is valuable for optimizing not only email campaigns but, also, the broader marketing strategy, helping ensure a smoother and more efficient path to conversion.

6. Web traffic and conversions

While metrics such as open rates and CTRs provide insights into engagement within the email itself, tracking web traffic and conversions offers a more comprehensive view of how these interactions translate into meaningful outcomes, such as sales, sign-ups, or downloads.

By monitoring web traffic generated by email campaigns, your brand can assess the effectiveness of its email content in driving recipients to your website. By employing tracking links and UTM parameters (snippets of text that can be added to links for tracking purposes), you can see exactly how much of your website’s traffic is coming from your email campaigns. This data is crucial for evaluating the real-world reach of your emails and understanding how they contribute to your overall digital presence. High web traffic from email campaigns indicates that your emails are successful in encouraging recipients to visit your site.

Beyond just driving traffic, the ultimate goal of most email marketing campaigns is to generate conversions. Conversions can take various forms, including making a purchase, filling out a form, signing up for a newsletter, or downloading a resource. By tracking these conversions, you can measure the effectiveness of your emails in achieving your business objectives. Conversion data helps you identify which email elements — such as subject lines, content, offers, and CTAs — are most effective in prompting recipients to complete desired actions.

In addition, analyzing web traffic and conversions provides valuable insights for optimizing your email marketing strategy. If you notice that an email campaign is generating high traffic but low conversions, it may indicate issues with your landing page or the alignment between the email content and the landing page. This insight can allow you to make necessary adjustments to improve the user experience and increase the likelihood of conversions.

7. Bounce rate

Bounce rate refers to the percentage of emails that are not successfully delivered to intended recipients’ inboxes. These bounces can be classified into two categories: hard bounces and soft bounces. Hard bounces occur when an email cannot be delivered due to permanent reasons, such as an invalid email address. Soft bounces, on the other hand, are temporary issues, such as a full inbox or a server problem. Understanding and managing bounce rates is essential for maintaining a healthy email list and ensuring that your messages reach your intended audience.

High bounce rates can signal a variety of problems that need immediate attention. For example, they may indicate that your email list contains outdated or incorrect addresses, which can harm your sender reputation and reduce deliverability. Email service providers (ESPs) monitor bounce rates to assess the quality of your email list and your sending practices. Consistently high bounce rates can lead to your emails being marked as spam or even being blocked by ESPs, severely limiting the reach and effectiveness of your email marketing campaigns.

Regularly measuring and analyzing bounce rates helps you maintain the integrity of your email list. By identifying and removing invalid addresses, you can improve your list quality and increase the likelihood that your emails will be delivered to active and engaged recipients. This practice enhances deliverability but also boosts your sender reputation, as ESPs view low bounce rates as an indicator of a well-maintained and engaged list.

Further, bounce rate analysis can provide insights into potential issues with your email content or sending practices. For example, if you notice an unusually high number of soft bounces, it may suggest that your emails are too large or contain elements that are triggering spam filters. Addressing these issues can improve deliverability and help ensure that your messages are reaching your audience.

8. Unsubscribe rate

The unsubscribe rate refers to the percentage of recipients who opt out of your email list after receiving a campaign email. While it might seem disheartening to lose subscribers, understanding and monitoring this metric can help you improve your email marketing strategy and ensure that your content remains relevant and engaging to your audience.

A rising unsubscribe rate can signal several issues that need prompt attention. It may indicate that your content is not meeting the expectations or interests of your audience, that you are sending emails too frequently, or that your messaging is perceived as irrelevant or “spammy”. By analyzing the context around unsubscribe spikes — such as the specific email content, the timing, or changes in frequency — you can pinpoint what may be driving recipients to leave your list. This feedback can be invaluable for adjusting your strategy to better align with your audience’s preferences.

Regularly monitoring unsubscribe rates can also help you maintain the quality of your email list and content. A lower unsubscribe rate suggests that your emails are resonating with your audience and providing value, which is essential for building long-term relationships with your subscribers. By continuously refining your content and approach based on unsubscribe data, you can foster a more engaged and loyal audience, ultimately, leading to better campaign performance and higher conversion rates.

Additionally, understanding the reasons behind unsubscribes can guide you in creating more targeted and personalized content. If certain segments of your audience are unsubscribing at higher rates, it may be beneficial to reevaluate your segmentation and tailor your messages more precisely to their interests and needs. This approach can reduce unsubscribe rates and enhance overall engagement by helping ensure that your content is relevant and valuable to each recipient.

9. Spam complaint rate

The spam complaint rate refers to the percentage of recipients who mark your email as spam. This metric is important because it directly impacts your sender reputation and email deliverability. Understanding and addressing spam complaints can help you maintain a healthy email list, improve your content, and ensure your emails reach your intended audience.

A high spam complaint rate is a red flag for email service providers, indicating that your emails are unwanted or irrelevant to a significant portion of your audience. ESPs use spam complaints as a key factor in determining the credibility of your sender domain. If too many recipients mark your emails as spam, your sender reputation can suffer, leading to your emails being filtered into spam folders or blocked altogether. Therefore, monitoring this metric is essential in preserving your ability to reach subscribers’ inboxes effectively.

Spam complaints often arise from various controllable issues, such as sending emails too frequently, failing to meet audience expectations, or using misleading subject lines. By analyzing when and why spam complaints occur, you can identify patterns and make necessary adjustments. For example, if a specific type of content or email frequency correlates with higher complaints, you can modify your approach to better align with your audience’s preferences. Additionally, ensuring that your emails provide clear and easy options for recipients to unsubscribe can reduce frustration and minimize spam complaints.

Spam complaint data can also offer insights into the overall quality and relevance of your email content. If recipients are consistently marking your emails as spam, it suggests that your messaging is not resonating with your audience. This feedback can be invaluable for refining your content strategy, improving targeting and segmentation, and enhancing the overall user experience. Finally, by addressing the root causes of spam complaints, you can create more engaging and valuable emails that your audience looks forward to receiving.

10. Email engagement metrics

Email engagement metrics go beyond basic measures like open rates and click-through rates to include actions such as forwarding, replies, and social sharing. By tracking these deeper levels of interaction, marketers can gain more comprehensive insights into the effectiveness of their campaigns and the true impact on their audience.

Forwarding can be a powerful indicator of the value and relevance of your email content. When recipients forward your emails to others, it shows that they find the content compelling enough to share. This not only extends the reach of your brand’s campaigns but also indicates high levels of trust and endorsement from your audience. Monitoring forwarding rates can help you identify the types of content that resonate most strongly with your subscribers, and you can leverage this information to create more shareable and engaging emails.

Replies are another important engagement metric, reflecting direct interaction and interest from your recipients. When subscribers take the time to respond to your emails, it signifies a high level of engagement and can provide valuable feedback or inquiries. Tracking reply rates helps you gauge the effectiveness of your CTAs and the relevance of your content. Further, replies offer an opportunity to build deeper relationships with your audience members by responding promptly and personally to their questions or comments.

Social sharing metrics, including shares on platforms like Facebook, Twitter, and LinkedIn, provide insights into how well your email content performs in broader digital channels. When your brand includes social sharing buttons in its emails and recipients click them to share your content on social media, it amplifies your message and attracts new potential subscribers. Analyzing social sharing data helps you understand which content generates the most interest and engagement across various social platforms. This information can guide your content creation and distribution strategies, helping you ensure your emails are optimized for social sharing and reach a wider audience.

Other engagement metrics, such as time spent reading the email and interaction with multimedia elements, can also offer valuable insights. For instance, tracking how long recipients spend reading your emails can indicate the overall interest and engagement level, while interactions with videos, images, or interactive elements can reveal the most engaging content formats.

11. List growth rate

List growth rate refers to the rate at which your email subscriber list is expanding over a specific period. This metric reflects the success of your efforts to attract new subscribers but it also indicates the overall health and potential reach of your email marketing campaigns. Understanding and optimizing list growth rates can help you sustain long-term engagement and achieve your marketing goals.

A steadily growing email list is a positive indicator that your brand is attracting interest and that your lead generation strategies are effective. By tracking list growth rate, you can evaluate the impact of various tactics such as content marketing, social media promotions, website opt-in forms, and events. For instance, if you notice a spike in new subscribers following a particular campaign or content piece, it suggests that your approach is resonating with your audience and can be replicated or expanded upon.

Conversely, a stagnant or declining list growth rate can signal potential issues that need to be addressed. It might indicate that your lead-generation tactics are no longer effective, or that your content is not engaging enough to encourage sign-ups, or that your opt-in process is too cumbersome. By identifying these challenges early through regular monitoring of list growth rate, you can make necessary adjustments to your strategy, such as improving your CTAs, simplifying the subscription process, or enhancing the value proposition of your email content.
In addition, list growth rate can reflect subscriber satisfaction and retention. A healthy growth rate often correlates with low unsubscribe rates and minimal spam complaints, indicating that your existing subscribers find value in your emails and are likely to recommend them to others. This organic growth through referrals is a strong testament to the quality and relevance of your content.

12. Overall ROI

Tracking the overall return on investment (ROI) of your email campaigns can provide clear indications of their effectiveness and profitability. ROI is calculated by comparing the revenue generated from your email marketing efforts to the costs incurred in executing those campaigns. Understanding your email marketing ROI helps you determine the value of your investment, identifies areas for improvement, and makes informed decisions to optimize future campaigns.

One of the primary benefits of measuring ROI is that it offers a comprehensive view of the financial performance of your email marketing strategy. By analyzing ROI, you can assess whether your campaigns are driving sufficient revenue to justify the resources allocated. This includes direct costs, such as software and design expenses, and also indirect costs like the time and effort spent on your email campaigns by your marketing team. A positive ROI indicates that your email marketing efforts are generating more revenue than they cost, proving their effectiveness and contributing to your overall business goals.

Furthermore, tracking ROI allows you to identify the most successful elements of your campaigns. By understanding which emails, subject lines, content types, and CTAs generate the highest returns, you can replicate these strategies in future campaigns to maximize profitability. Conversely, if certain elements or campaigns yield a low ROI, you can analyze the underlying reasons and make necessary adjustments. This iterative process of measuring, analyzing, and refining helps you continuously improve your email marketing strategy and achieve better results over time.

Measuring ROI also provides valuable insights for budgeting and resource allocation. By knowing which campaigns deliver the highest returns, you can allocate more resources to those initiatives and reduce spending on less effective ones. This helps ensure that your marketing budget is used efficiently, maximizing the impact of your investments and driving higher overall returns for your business. Additionally, demonstrating a positive ROI to stakeholders can help secure future funding and support for your email marketing efforts.

Elevate your email-marketing efforts with help from a team of pros

Could your brand’s email-marketing campaigns benefit from some expert guidance and experience-driven insights? At Brandon, our team of certified brand strategists and data-driven marketing experts has helped clients in a range of industries boost their email open rates, click-through rates, ROI and more. Further, our fully integrated marketing firm can cover the full spectrum of your brand’s marketing needs, including email marketing, social media, brand strategy, web design, creative, media, e-commerce, analytics, SEO and conversion rate optimization. To get started with help ranging from a simple website analysis to a comprehensive strategy tailored to boost the performance of all your marketing campaigns, contact us today.