12 Email Metrics You Need to Track
As an email marketer, I often get asked the question, “What do you like about Email as a marketing channel?”
Well, many reasons… but if I must pick one, it’d be the ability to track customers’ behavior at a granular level using various metrics, which are crucial to gaining insight into how your campaign performs and how to fuel future growth for your program. With software integrations, you can even track retention metrics like LTV, Repeat Purchase Rate, and time between purchases for email cohorts or each recipient.
But which email metric should you measure?
In this article, we’ll explore the essential email metrics: their definitions, their importance, and strategies for optimization. The metrics are categorized into three groups — engagement, conversion, and deliverability — to provide a clear understanding of their roles, and let you jump to the category that interests you.
Be sure to reference this spreadsheet I created while reading this blog post so you can follow along and get a better understanding of what email reporting looks like IRL!
Let‘s get started!
TL;DR
Engagement Metrics
Open Rate (OR)
Click-through Rate (CTR)
Click-to-open Rate (CTOR)
Read Rate
Conversion Metrics
Delivery Conversion Rate (DCVR)
Click Conversion Rate (CCVR)
Average Order Value (AOV)
Revenue per Delivery (R/D)
Deliverability Metrics
Unsubscribe Rate
Bounce Rate
Spam Complaint Rate
Deliverability Rate
Engagement Metrics
#1 Open Rate (OR)
Open Rate = (Number of Emails Opened / Number of Emails Delivered) x 100
What: The percentage of email recipients who opened your email. Elements like Subject Line, Preheader, Sender Name, Send Time, Targeting, and even Deliverability all play a part in OR.
To track opens, your Email Service Provider (ESP) or Customer Data Platform (CDP) like Klaviyo, Iterable, and Mailchimp embeds a tracking pixel — a tiny invisible graphic — in your email. When a contact opens the email with images enabled, the graphic is downloaded, which is then recorded as an open.
Subject line, Sender Name, Preheader, and even your brand logo play a part in OR.
Why: Email marketers track OR because it can be valuable when…
Used it as a comparative metric to compare campaigns sent to the same or a similar list.
You only view the OR of non-Apple users to gain insight into the “true” open rate (more on this below).
Why under those specific situations? Because OR can be unreliable for a few reasons:
Plain-text campaigns, such as automated replies, generally do not download the tracking pixel, so opens can’t be tracked.
Similarly, open tracking won't work if your subscribers or their email client, e.g. AOL, block email images.
More importantly, Mail Privacy Protection (MPP), launched in 2021 by Apple, tends to inflate OR as it pre-loads tracking pixels for users who opted in, making it a relatively unreliable metric.
So, don't rely too heavily on OR for overall email success, especially if your audience is mostly Apple Mail users. Focus on other metrics like click-through rate, conversion rate, and revenue per delivery, depending on the goal of your campaign.
How: Even though OR is not as reliable, it doesn’t mean you don’t have to optimize for it. Boost your OR by adopting some of my tried-and-true best practices below:
Drive a sense of newness in your SL and/or PH to prompt recipients to check out your content, using words like “new,” “meet,” “limited edition,” and “launched”.
Create a “Curiosity Gap” that can only be filled by opening and reading the email. For instance, “Have you heard?” “Coming Soon…” “New arrivals you don’t want to miss”.
Optimize every element displayed in the inbox — subject line, preheader, sender name, email address, personalization, and more — all work hand-in-hand to create a compelling message.
Want to learn more? Check out my full list of best practices here.
#2 Click-through Rate (CTR)
Click-through Rate = (Number of Emails Clicked / Number of Emails Delivered) x 100
What: The percentage of email recipients who clicked on links in a given email. Unlike Click-To-Open Rate (CTOR), which will be discussed next, the CTR leaves open out of the equation, giving you an unbiased look at email performance.
Why: It’s important because click is one of the critical steps in a conversion path. In most cases, the goal of an email campaign is to drive recipients to take a certain action on your website upon clicking an email, like placing an order. If a reader doesn't click, it could be either because your content isn’t compelling enough, or they simply aren’t interested in what you show them.
How: Some tips on improving CTR…
Place the main Call-To-Action (CTA) higher up or above the fold to drive immediate clicks upon opening (with words and messaging that drive urgency and FOMO).
Include prominent CTAs throughout your email to encourage clicks.
Leverage “the sandwiching effect” — placing one CTA at the top of an email and one at the bottom — so readers don’t have to scroll all the way up for the main CTA, especially in a long-form email.
#3 Click-to-open Rate (CTOR)
CTOR = (Number of Emails Clicked / Number of Emails Opened) x 100
What: The percentage of recipients who opened AND clicked on links in a given email.
Why: CTOR is valuable at measuring the effectiveness of email content because it’s based on readers who have actually viewed it. Is your content compelling enough to prompt readers to click after they expressed interest (i.e. open)?
How: In addition to the tips for CTR mentioned earlier…
Ensure the body content meets the expectations set in your recipients’ inbox. If it’s a sale, provide them with the details such as the offer, deadline, coupon, and any compelling info.
#4 Read Rate
Read Rate = (Number of Emails Read / Number of Emails Opened) x 100
What: Read Rate measures how many of your emails opened were actually read. Most email tools define “read” as an email opened for eight or more seconds. With Litmus, you can get a detailed view of read time: people who glanced (less than 2 seconds), skimmed (2-7 seconds), and read (8+ seconds).
Why: For most email campaigns, especially revenue-driving ones, you’d want to focus on conversion metrics since your goal is to drive as many conversions as possible. However, if you’re sending a content-oriented campaign without a clear CTA or action like editorial and privacy notices, this is a useful metric since your goal is to inform, educate, or entertain readers through your email content.
How:
Ensure all the content shown in recipients’ inboxes, like the SL and PH, matches your email content.
Place compelling, captivating content above-the-fold to catch readers’ attention and keep them engaged throughout the email.
Craft relevant email content your readers care about.
Conversion Metrics
#5 Delivery Conversion Rate (DCVR)
Delivery Conversion Rate = (Number of Conversions / Number of Emails Delivered) x 100
What: The percentage of email recipients who converted from your email. A conversion could be anything from placing an order to downloading an ebook.
Why: Unlike Click Conversion Rate (CCVR), which is based on clicks, DCVR gives you a high level of how your email performs. The downside is that it doesn’t provide a clear picture of which touchpoints or parts of your email/site work or don't work (and that’s why we also need to look at CCVR).
What I like about this metric is that you can use it to quickly project conversions for your future campaigns by multiplying the est. recipients of a given email by the average DCVR of the campaign type, e.g.,
300,000 Subscribers * 0.2% Average DCVR = 600 Projected Conversions
Granted, there are other sophisticated methods for estimating conversions, but sometimes you just want something quick and easy!
How:
Optimize every touchpoint of your email and site to encourage customers to open, click, and ultimately convert — convincing product blurbs, appealing images and/or videos, prominent CTAs, streamlined checkout process, etc. Every touchpoint matters!
#6 Click Conversion Rate (CCVR)
Click Conversion Rate = (Number of Conversions / Number of Emails Clicked) x 100
What: The percentage of email recipients who clicked AND converted.
Why: Unlike DCVR, Click Conversion Rate narrows down the scope telling you the efficacy of your email content and the conversion journey of your site. It's important to remember, though, that some conversions don't happen immediately, but that doesn't mean your efforts are wasted! Just aim to get your CVR as high as possible every time you send out a campaign (or at least improve it over time) while continuing to provide relevant content to your subscribers. When they need it, they will think of you and convert ultimately.
How:
Craft relevant emails that meet recipients’ expectations from SL, email content, to the site experience.
#7 Average Order Value (AOV)
Average Order Value = (Revenue Generated / Number of Orders)
What: The average dollar amount spent per order, a key metric for e-commerce.
Why: Increased AOV = increased revenue. By increasing your AOV, you can generate more revenue without reworking your marketing budget, plan, or resources. Before brainstorming ways to increase the number, consider the value you can add to your customers' shopping experience rather than focusing on moving products just for the sake of it. Without a clear value proposition, it will be challenging for customers to add items they don’t intend to get.
How:
Personalize email, site content, and product recommendations that provide value based on user profile and shopping behavior.
Up-sell, cross-sell, and “bundle” throughout users’ shopping journey.
Create a free shipping threshold that encourages customers to increase their spending. Keep in mind the threshold should be realistic, but still high enough to cover shipping costs.
#8 Revenue per Delivery (R/D)
Revenue per Delivery = (Revenue Generated / Number of Emails Delivered)
What: The monetary value of every delivered email.
Why: Email marketers love this metric as it provides a high level view of your campaign performance and allows you to compare the effectiveness of your campaign with one another. You can also use it to forecast email revenue as you plan for the months ahead. For example, a product launch email will be sent to a list of 300,000 active subscribers. The average R/D of a similar launch is $0.8, so you project that…
300,000 subscribers * $0.8 R/D = $240,000 projected revenue
If the actual R/D of a campaign is lower than the average, it could mean your content, product, or shopping journey isn’t hitting the right note with your audience.
You can also use it to monitor the efficiency of your email program. Make sure your email program's R/D grows along with your mailing list as it means you're converting subscribers at the same (or a better) rate.
How: Almost every component of your email program and touchpoints will affect your R/D: audience, deliverability, email content, landing page, and more. So strive for continuous improvements, e.g.,
Maintain a list of engaged, active subscribers who are interested in converting.
Craft compelling emails that resonate and convert.
Optimize customers’ shopping journeys — from the landing page to the confirmation page (yes, you can also cross-sell/ up-sell on the confirmation page to increase AOV).
Deliverability Metrics
#9 Unsubscribe Rate
Unsubscribe Rate = (Number of Unsubscribes / Number of Emails Delivered) x 100
What: The percentage of email recipients who opted out of your emails. In general, you want to aim for less than 0.5% to keep your deliverability healthy.
Why: Maintaining a low unsub rate is crucial because it impacts your deliverability performance. As with spam complaints or bounces, an increase in unsubscribes could indicate to inbox providers that you're sending unwanted emails to your list. This damages your sender reputation and can eventually lead to more of your emails landing in spam than in the inbox.
This may sound contradictory, but make unsubscribing easy and painless for your subscribers! Getting rid of unengaged or uninterested subscribers is better than being marked as spam.
How:
Stick to email opt-in best practices and make sure you only send emails to people who explicitly agree to receive your communications.
Send relevant content that resonates with your subscribers.
Create an email preference center that allows subscribers to opt down (content or frequency), instead of only opt-out.
#10 Bounce Rate
Bounce Rate = (Number of Emails Bounced / Number of Emails Sent) x 100
What: The percentage of sent emails bounced or undelivered — whether it’s a “Soft Bounce” or a “Hard Bounce”:
Soft Bounce: A temporary bounce occurs because…
The recipient’s mailbox is full.
The email has been temporarily suspended.
The email server experiences outages (and thus is undeliverable).
Your emails are marked as spam many times.
Hard Bounce: A permanent bounce occurs because…
The email address doesn’t exist (e.g. typo).
The email address blocks your emails.
The email address has been deactivated.
Why: If your account has a high bounce rate, it can negatively impact your deliverability and sender reputation. As your bounce rate increases, inbox providers may move your emails to spam because the increase signals poor list hygiene and/or problematic list acquisition practices.
Therefore, the metric should be monitored at least once a week so you can act quickly before the situation becomes a problem. Ideally, you want to keep it under 0.4% (or at least a delivered rate of 99.6%).
How:
Understand how your ESP handles soft and hard bounces. For soft bounces, does your ESP automatically resend your message? At what point does it suppress an email address that soft bounces repeatedly? For hard bounces, does it automatically check and correct email address typos? Does it automatically suppress any email address that hard bounces?
Review and clean up your email list regularly, e.g., correct email address typos, and remove expired or deactivated email addresses (or move them to a suppression list).
Set up email double opt-in asking new subscribers to verify their email address before they officially sign up for your email list.
A simple graph explaining the difference between Hard Bounce and Soft Bounce.
Source: Mixwithmarketing
#11 Spam Complaint Rate
Spam Complaint Rate = (Number of Spam Complaints / Number of Emails Delivered) x 100
What: The percentage of email subscribers who mark your email as spam.
Why: Maintain the rate below 0.05% because a high spam complaint rate will hurt your deliverability performance and sender reputation, prompting your emails to land in subscribers’ spam folders. If you see a rise, take immediate action to lower this metric.
How:
Make the unsubcribe link easily accessible for subscribers, so they can opt-out rather than mark your email as spam. A spam complaint harms your deliverability far more than an unsubscribe.
Send emails to subscribers who explicitly opted into your mailing list.
Enable double opt-in.
#12 Deliverability Rate
Deliverability Rate = (Number of Non-junked Emails Delivered / Number of Emails Delivered) x 100
What: a.k.a. inbox placement rate. The percentage of subscribers who receive your email in their primary inboxes, rather than junk or spam folders. The difference between delivered and deliverability is that an email counts as delivered even if it’s in junk, whereas deliverability specifically looks at whether your emails actually land in your subscribers’ inboxes.
Why: It’s important to keep your deliverability rate > 99% to ensure most of your subscribers see your emails and take action or convert. Otherwise, your efforts might be wasted.
How: All the deliverability metrics above, along with other numerous factors unidentified, play a part in your deliverability rate, so try your best to follow as many best practices as possible, such as:
Authenticate and fully warm up your email infrastructure.
Maintain a list of engaged, active subscribers.
Send relevant, engaging content.
Create a Sunset Flow that sends a series of emails with the goal of reactivating churned subscribers. If they don’t engage at all, consider moving them to a “suppression list” to be suppressed when sending campaigns.
Next Steps
Now that you've gained an understanding of these essential email marketing metrics, it's time to put your knowledge into practice. Begin by analyzing your current email campaigns to identify areas for improvement. Leverage the insights gained from these metrics to make data-driven decisions and optimize your email marketing strategy.
Once you know which metric you want to optimize for, consider conducting A/B testing like different subject lines, content, and CTAs to see which variations perform best. Monitor your progress and continue refining your approach to maximize your email marketing ROI.
Remember, the key to email marketing success is a continuous cycle of learning, testing, and improving. Good luck!
