Email Marketing Analytics: KPIs Deep Dive, Metrics, Goals and Reports
By Matej Cambal
Email marketing key performance indicators (KPIs) can be measured in many ways.
Look at any email marketing tool and you’ll find dozens of KPIs you can use and monitor. But blindly trusting these metrics can result in misinterpreted data and bad decisions.
To actually succeed with your email marketing KPIs, you need to focus on two things: email deliverability (your ability to reach the recipient) and content performance (your ability to convince the recipient to reach the goal you set up).
Let's go through all the most important email marketing KPIs for measuring the success of your email campaigns, along with benchmarks to help you understand what numbers you should aim for.
How to Measure Email Marketing Success
Step 1. Understand Everything You Can Measure in Email Marketing
Understand what KPIs can be measured, what pitfalls you can encounter when evaluating them, and what decisions the email marketing metrics can lead to.
Step 2. Creating Goals
What are your email marketing goals? Do you use it for customer re-engagement, for sending bulk newsletters, or for targeting individuals with e-commerce personalization tactics based on their most recent behavior?
Different email marketing campaigns will have different goals. You should not expect every email to bring you revenue. Sometimes, all you are looking for is to re-engage with the customer and explain your unique selling propositions, hopefully leading to a purchase later.
Step 3. Define Your Email Marketing KPIs
Once you know the goals for your email campaign, you can start with defining the KPIs. It’s important to focus on both “positive” KPIs, such as revenue uplift or open rate uplift, as well as “negative” KPIs, such as keeping your unsubscribe rate low.
Step 4. Track Email Marketing Metrics
Tracking metrics should be automatic with most modern email solutions, or customer data platforms (CDPs) that offer execution. The benefit of using a CDP is that you can see all email related actions in a single customer view.
Step 5. Evaluate
Evaluating email marketing KPIs can be tricky — some of them need to be looked at daily, some weekly, and others you can only check monthly.
Check these daily: open rate, open-rate variation, bounce rate, and soft-bounce rate. These metrics might help you spot incoming problems.
Check these weekly: overall email campaign performance, email campaign conversion & revenue reporting, click-through rates, spam-complaint rates, unsubscribes and active audience trend.
Check these monthly: opens per customer, revenue per customer, mobile open rate, email client share, spam score checks.
Step 6. Improve
Knowledge of benchmarks will help you prioritize what needs to be improved. If you don’t like your conversion rates for a newsletter, but you’re still beating benchmarks, then there might be another area to focus on where you can get a bigger improvement for the same effort.
To set up a email marketing strategy, you have to be confident in the numbers you see reported. You have to understand how the metrics influence each other and what could go wrong by trying to improve one area.
It’s completely normal to feel overwhelmed by the sheer size of the reports — there are lots of different metrics, and it’s difficult to even know where to start. If you feel this way, start at the beginning of the funnel: your customers, your audience criteria, and your email frequency.
Once you’re happy with this part of the funnel and you’re getting results you like, you can move on to the next steps: delivery rate, open rate, click rate, and eventually revenue.
Remember that you’ll need to be patient. Big changes, especially in email marketing, take time. Set reasonable timelines and don’t expect miracles after two email marketing campaign sends. Email marketing is a complex system, and it depends on more than just your performance. There are external factors at play. You need to test and find what works for you, your goals, your customers, the mailbox providers, and those trying to fight spam.
But before you do anything else, you need to understand email marketing KPIs. So let’s take a look at what they are and how they’re defined.
Email Marketing KPIs
Before you even send an email marketing campaign and start measuring metrics, you need to understand the audience that you market to.
Email Audience Trend
As you gain subscribers, you also lose subscribers — this is a natural process. Knowing that your audience is declining, and knowing this early, will help you prevent bigger revenue issues months down the line. it enables you to take actions, to understand why subscribers are leaving, and what you need to change.
Active Audience Trend
It’s also vital to monitor the growth or decline of your active audience. These are the subscribers that engage with most of your emails, bring the most revenue, and are the only ones with whom you should communicate with a high frequency.
Catching any issues early and setting up a good re-engagement program should help you avoid any shrinkage of your active audience.
Delivery of an email is usually the first thing measured — it means that your email was accepted by the recipient server. In the case of a bigger deliverability issue, you would see your delivery rate drop, which might indicate that you are being blocked completely.
As long as your database is clean, you should be achieving a 99% delivery rate or higher, although you might see lower delivery rates on programs such as double opt in or a welcome program, where new email addresses enter your list.
A delivery rate below 97% should get your attention. You might need to check how you’re collecting email addresses. Using real-time validation for collection can be helpful here.
It’s important to note that a high delivery rate does not mean high inbox placement. Your email could be getting delivered, but winding up in spam folders, where the recipient won’t notice it.
Hard Bounce Rate
The bounce rate informs you about hard bounced emails: adresses that are permanently unreachable. You should automatically exclude any bounced addresses from your list. Failure to do so will lead to your emails being blocked completely.
A high bounce rate can be caused either by already being blacklisted, or more commonly by sending to invalid email addresses. Sending emails to an invalid email address can also cause a myriad of other issues.
You can find out what’s happening by looking at status messages or code that was sent back to you.
Some email providers will block a domain with 1%+ bounce rates for bulk email campaigns, as it indicates bad email list health. In general, keeping your bounce rate below 0.5% is a benchmark you should aim for.
Soft Bounce Rate
Your soft bounce rate informs you about temporary issues in your emailing. This doesn’t mean it’s not important to monitor, as it can hint at bigger issues. If you ignore these warnings, you will eventually encounter hard bounces and a drop in delivery rates.
Frequent causes for soft bounces are temporary blacklisting, full mailboxes, connection errors, and greylisting. To avoid these, make sure your email list is clean and that you use best sending practices. You should aim for a less than 0.5% soft bounce rate.
If you encounter a big spike in soft bounces, it could be a mistake or bad filtering from the recipient domain. You can try solving this with your ESP, which will be able to reach out to the recipient domain.
Open rate is the second most important email deliverability metric. It shows you that emails are reaching the customers inbox, and that either the brand or the subject line caught their attention. Most brands calculate this as unique opens, since counting all opens can skew the results.
Senders with good list health and an engaged audience typically reach 30-40% open rates on bulk emails. The golden standard to reach is at least 20%+.
On automated or triggered personalized email marketing campaigns, you might see open rates between 40% and 70%. This is possible with smaller audiences, microsegmenting, and very relevant content.
The open rate is determined by displaying a 1px x 1px image at the top of the email. When the email is opened, the image is downloaded, which lets the tool know who opened an email and when. However, there is a downside to this method: if images are blocked by the email client, there is no way to track opens.
Total Open Rate
This metric will help you understand how many customers are coming back to reopen an email. This is helpful for finding out whether customers are returning to emails with, for example, USPs or loyalty program information. If they are, you might think about sharing that information in an easier-to-find way, so they’re not searching for old emails.
Open Rate Variation
When you compare open rate results between different domains, you might see that one domain is performing much worse than your best performing one. For example, Gmail might have open rates of 30%, but Hotmail only reports 14%. This would hint at inbox placement issues with Hotmail.
You will always see some difference due to different types of customers using different mailbox providers, but if the difference is 30% or more, it deserves more attention.
Opens Per Customer
This metric is handy if you are trying to adjust your email frequency. Select a time period for which you are calculating the metric (we usually look at the last seven or 30 days) depending on how engaged the audience is and how frequently you are sending already.
It’s hard to establish a benchmark here, since it’s very dependent on the frequency of your emailing.
If you send 15 emails a month, but the average opens per customer in 30 days is just 1.6, you might have to reconsider your sending frequency. You can still send more to the most engaged audience, but tone it down for the less engaged.
Sending fewer emails with the same opens per customer would also mean an increase in your open rate.
Understanding when your customers are engaging with your emails can prove helpful for email campaign timing and getting better conversion rates. You should send emails when customers are ready to open them, which can vary a lot from individual to individual. But even aggregated results can show you where there’s room for improvement. An example of how to measure this metric is in part six (useful reports).
Mobile Open Rate
Are you optimizing content for desktop, mobile, or both? Do you properly test all major mobile devices? You might find you are spending a lot of time optimizing your emails for the 0.1% of your subscribers that use Outlook, but the majority of your revenue might come from the 70% of your subscribers that are iPhone users.
Although it’s not always possible to identify the device used to open an email, you should try to do so where possible. This is usually parsed from “user-agent” and some tools will do it automatically.
This metric shows how many customers, out of all those that received an email, clicked on the content. This is essentially reporting on two things at once: how many customers opened an email and how many clicked. It is mostly useful at evaluating the overall success of a email marketing campaign and comparing the performance of different campaigns.
Low CTR might mean two things: either the customers were not convinced to open the email, or they opened it but weren’t convinced to click through. To help you understand which case you’re dealing with, you need to overlay this metric with the Click-to-Open rate, which we describe next.
A great CTR to aim for is 4%+, although on average brands typically see something just under 3%.
While similar to the previous metric, this metric is calculated based on emails opened, not delivered. This means it better reflects the performance of the content of your email.
If you see low CTR, but high CTOR, this usually means the customers were not convinced to open an email, but once they did, they engaged. You can fix this by looking at why the customers are not opening the email.
You might have great content with an above-average CTOR, but if the subject line is underperforming, most people won’t see the awesome content you prepared.
On the other hand, low CTOR means the content did not perform well. Even if you targeted the correct customers with a compelling subject line, the content was below the expectations of your customers.
Companies often achieve a 15% CTOR, which is a good benchmark to aim for.
Unsubscribe + Spam Complaint Rate Per Email
Reporting on unsubscribes is important for understanding the other side of the email business: how many people completely lost interest in your email marketing efforts, or worse, your brand?
Your email campaign might have performed very well thanks to a compelling subject line. But what if there are many people who, after opening the email, felt misled by the content and unsubscribed immediately? Most of the time, those subscribers are lost forever.
To lower your unsubscribe rate, you should limit your sending frequency for less engaged customers and make your emails relevant to the customer receiving them. You will always have some number of unsubscribes, but spikes should warrant an investigation on your side.
Unsubscribe rates should be below 0.5% on a campaign level. We also recommend including spam complaints into this metric, as these are also considered unsubscribes, just done differently. This is a user who thinks your email is spam and marks it as such, which means you should immediately stop sending them emails. Spam complaints should be less than 0.01% of your send.
Conversions & Revenue & AOV
The correct attribution of conversions will make or break your email revenue reporting. Most companies today use last-click attribution, with an attribution window of 24 hours or three days, depending on email frequency.
If you are sending two emails a week, it would be more accurate to select a longer time attribution window than a brand sending emails every day.
Looking at revenue and AOV alongside the number of conversions will help you understand if certain email marketing campaigns are driving high-value purchases, or if your triggered scenarios, like an abandoned cart email, are working.
Understanding how campaigns create revenue is important for prioritizing which campaign should be further developed, which content works, and which customer segments perform the best.
Some brands also look at conversion rate from opens instead of delivered emails. This better reflects the effectiveness of the content and the offer itself, but it should not be used exclusively.
A conversion rate benchmark for newsletters is 1%+ and for triggered emails is 3-5%+, with some very specifically targeted or heavily incentivized emails achieving 15%+.
Revenue Per Open
Calculating revenue per open is important when changing your high-level email marketing strategy, audience management, or frequency capping. Sometimes, these changes may lead to more opens being generated, so you should know whether revenue per open is increasing or decreasing.
This is not an important email marketing metric by itself, but should be looked at when evaluating revenue changes.
Revenue Per Subscriber
Revenue per subscriber is very important for two key areas: measuring your email costs and revenue, and measuring the impact of high-level changes to your email strategy.
Time Spent Viewing Email
Some tools allow you to report on the time spent reading an email. This helps you to understand whether the content is important to customers, and whether customers can quickly find what they were looking for. A short reading time and a click means that the customer found what was important almost instantly. On the other hand, a long reading time and no click might show that the content was not important.
As email read times are increasing recently, especially for mobile, you might find that your emails are too short, and you can fit more content in.
This is a metric to keep an eye on, but not a business-critical metric.
There are two types of “spam score” metrics: one that evaluates your content, and one that evaluates your “sender score”, which is dependent on your domain or IP.
Your content spam score looks at several factors: your image-to-text ratio, the use of “spammy” keywords, whether you include malicious links, and the technical setup of the email (e.g. missing DNS records like SPF or DKIM), and others depending on the ISP.
The ideal is to keep this score as low as possible – you can measure it using a dedicated tool.
Email Client Share
This metric is harder to measure, but it’s still helpful. It looks at the share of different email clients your customers are using.
This is parsed from “user-agent” information that the sender can see by using an open tracking pixel — but it doesn’t always result in valuable metrics. While you will be able to distinguish between iPhone and Outlook users, Gmail will report one string for all different clients using Gmail, no matter whether they’re reading on their desktop, app, or mobile version of the website.
Once you find the breakdown of your audience, you can allocate appropriate effort to optimizing for different email clients. If Apple Mail makes up 80% of your opens and you need to send out an urgent email, you know what device you should test on.
Email Marketing Goals
Now that you know the important email metrics, how can you use them to improve your marketing? In the end, you need to decide what your goals are — and that will determine how you use the metrics.
But before setting up your goals, you should be absolutely clear on the state of your email marketing analytics and understand your key challenges based on what your metrics are telling you.
Your emailing goals don’t need to be entirely based on metrics. They can be based on something more abstract, like wanting to include more personalization in your newsletters. The important thing is that your results need to be quantifiable and measurable. You will need to set different KPIs based on which metrics are important for your goals.
Let’s look at some goals that email marketers frequently set. We’ll start with the most complex and work towards more specific ones. We’ll also give you some KPIs to focus on for each goal.
Goal: Increase Email Marketing Revenue by X% in Y months
This is the most common, but also the most complex, goal that you can set for yourself. It is influenced by many factors, so it is usually wiser (and easier) to break it down into smaller steps and multiple KPIs.
Let’s start at the end of the funnel: a conversion. Conversions on the web or in an app can come from email in two ways: either directly from a click in an email, or indirectly (a customer gets an email but doesn’t make a purchase immediately, but later they remember the content from the email and come directly to the site to make a purchase).
There is no straightforward way to measure email’s influence on the latter scenario, so we need to start with a quantifiable goal: an increase in clicks and click-to-open rate.
You can improve these email metrics with the following tactics:
Test Your Email
Test the content, formatting, and images on multiple devices. Make sure your readers can engage with the content once they open the email.
Make it Easy to Convert
Don’t hide a button at the bottom of the email. Highlight the conversion goal multiple times and work on your CTA button – it’s your moneymaker. Set the right expectations at this stage.
Make the content personalized and relevant to the customer — whether that means targeting based on their favorite category, or using advanced recommendations that choose the best products for that target audience member. This tactic is usually the most effective one.
Let customers Give Feedback.
This can be done by encouraging a direct email reply (you might have noticed that “[email protected]” emails are slowly disappearing), giving customers a simple poll, or setting up a customized preference control center that allows customers to select the topics they are interested in and set the frequency with which they’ll receive emails.
Goal: Increase Active Audience Size by Y%
Two things influence your active audience size: customers becoming part of your active audience by engaging with an email, and customers leaving it by not engaging.
Start by improving your sign-up process. Is it as simple and straightforward as GDPR allows? Are the customers clear on what they are signing up to? Once they sign-up, do they receive a welcome email that sets expectations for the content they will start receiving from that day? If they don’t open the email, do you try to re-engage them with personalized communication, or do you just start churning out newsletters?
Do you make sure that customers have a good reason to re-engage? If you know a customer is about to leave your active audience, there are a few things you can try. Like offering an incentive, showing what they missed out on by not opening your emails.
Make sure to capture customers with re-engagement campaigns not just at the 90-day mark, but at different times, too: 150 days, 180 days, a year. Don’t be afraid to A/B test various incentives and messaging at this stage.
Goal: Increase Open Rates by X%
The open rate metric can be quite misleading, and the overall number doesn’t tell you the whole story. It’s important to establish a benchmark between different mailboxes. This helps to rule out any deliverability issues before you try to improve content.
If the variation in open rates for different mail providers is more than 30%, e.g. Gmail reports an open rate of 20% while Hotmail reports 11%, you should focus on improving your inbox placement with Hotmail.
If you are sure you don’t have any major deliverability or inbox placement issues, you can proceed with content improvements. Anything the customer sees is fair game for improvement.
Here are some items worth checking.
Is it obvious at first sight who the email is from? Try A/B testing which branding works best for you (using a personal name in the “From” might work for some more informal brands, e.g. Peter from Bloomreach).
Most of the time, keeping it simple is the winning variant. People like consistency, so don’t change the sender name too often. This might get you incorrectly flagged as a phishing or scam attempt by the recipient.
Here you can really flex your creative muscles. This is the most visible element of the email, so make it personal. Use any knowledge of the customer you have to make the subject line relevant, but not creepy. Focus on the brands, categories, and products the customer likes. If possible, do an automatic A/B test for 3-4 variants on a small portion of your database, wait for a few hours, and then send the winning variant to the rest of your customers.
Pre-header Text / Preview Text
Although slightly less visible than the subject line, customers still notice it. Make sure to use this space to “preview” what the content of the email will be like. You definitely shouldn’t show the following message: “If you can’t see the email properly, click here to view in browser” — this is a waste of valuable space.
This influences where your email is in the inbox. If you send your email at 6 AM, and the customer usually checks their emails after work, you might already be in the 10th position. You need to use your knowledge of when a customer opens their emails and be sure you land at the top of the inbox.
All of these improvements will lead to an increase of open rates. Of course, the person you’re sending to is also important. When it comes to the recipient, the same principles from the previous goals apply: be careful not to over communicate, be relevant to the individual customer, and make sure the frequency is acceptable.
Useful Email Marketing Reports
There are two major reports that will tell you most of what you need to know about your email performance, including both deliverability performance and campaign performance. These reports were created in Bloomreach, but you should be able to recreate them in the email marketing analytics program of your choice.
Email Domain Report
The first one is the email domain report, which shows you email marketing metrics for specific recipient domains. This will help you see any deliverability issues with a particular mailbox provider – and you can use open rate variance metric here. If a certain provider shows 30% lower open rate than the other, this is most likely due to bad inbox placement. Similarly, if there is any spike for soft bounces or hard bounces, you should look into what is causing those issues.
The second perspective, which uses mostly the same set of important metrics in a different format, is the campaign report. You can get this report by using the previous Email domain report, but in rows, you should use “campaign > campaign_name” instead of “email_domain”. You can also add “campaign > subject” as an extra row, in case you want to see the subject lines used, or if you tested various subject lines.
This allows you to monitor how your campaigns are doing, e.g. how is different content influencing the click rate, how are different subject lines affecting open rate, etc.
Soft Bounce / Bounce Report
If you spot any problems in the campaign or email domain report, you can use the following report to investigate further. This will help you understand where soft or hard bounces are coming from. Is it bad email list health or is your content being blocked?
Open and Click Time Report
To help you understand when customers are opening or clicking on your emails, and whether this is in-line with their usual shopping time, you can build the following report. You will see most of the opens and clicks happen after sending the campaign, but you might find out that this isn’t when your customers typically do their shopping.
At first sight, we can see a high open-to-purchase ratio before lunch, when the email is sent. But then we can see that customers are opening fewer emails but still shopping.
If we hide opens from this view and look at clicks only, we can see that there are spikes in clicks in the morning and late evening, but they don’t correlate with when purchases are happening.
Here you could benefit from using optimal send time prediction, as this would make sure every customer receives an email at their optimal time. If this prediction isn’t available to you, you can also use this for the segmentation of morning and evening shoppers, and send campaigns at two different times for these two segments.
Bloomreach Engagement Helps Improve Email Marketing KPIs
Email marketing KPIs are extremely important to measure and there’s a lot to digest. Your efforts depend on good email marketing analytics and aligning your KPIs in the right manner.
With this article as a guide, you can start working on improving your KPIs across the funnel, starting from the top.
What else will help? A technology stack that supports achieving your goals with email marketing analytics. Bloomreach Engagement is a single platform that combines the power of a customer data platform, an email service provider, artificial intelligence, marketing automation, and other web personalization capabilities, so your company can create key marketing campaigns across channels that drive revenue.
With Bloomreach Engagement, email marketers can unify all of their customer data and deliver connected customer experiences with a single solution. Bloomreach Engagement creates a single customer view for the email marketer that helps facilitate the creation of personalized product recommendations, personalized email campaigns, and so much more. Schedule a personalized demo today to learn more.