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Email Marketing KPIs 📊

Head West Team
Updated May 22, 2023

Ecommerce email KPIs and metrics that every company should be tracking (with benchmarks)

Once you’ve selected your email tool (read our guide on the best email platforms for eCommerce), the next step is to track and optimize the performance of your email marketing efforts. The old Peter Drucker saying "What gets measured, gets managed" is true for email. 

We put together this guide to cover the key email metrics that every eCommerce company should be tracking. We’ve also included benchmarks because the metrics are often meaningless unless you have something to compare them to.

Let’s dive in!

List Growth

Email popup (modal) collection rate

The first step in monitoring the performance of your email programing is measuring the performance of your list growth. What drives the growth of your list? The effectiveness of your email popup.

  • Email submits / email modal popups = email popup collection rate

Benchmark: >8%

How to improve? Test, test, test. The email popup is something that should be constantly tested. What imagery are you using? Do product photos perform better than photos with people in them? Test it. What offer are you using to entice visitors to enter their email? Test different formats. 

Tips: Mystery offers perform really well. Customers love mystery. Curiosity is built deep into human nature, and visitors will often subscribe to emails just to find out what the mystery offer is. 

Dr. Squatch's Email Popup (Modal)


Bounce Rate

Once you have someone subscribed to your email list, the next step is to make sure your email reaches their inbox. The bounce rate measures the number of emails that don’t reach a subscribers inbox.

  • Bounced emails (emails that don’t reach the inbox) / sent emails = email bounce rate

Benchmark: <1%

How to improve? Make sure that you have implemented all of the email authentication protocols SPF, DKIM, and DMARC. Also set up a dedicated sending domain. Have you sent a lot of emails over a short period of time? Make sure to ‘warm up’ the account before sending to huge lists. Check to see if there is any specific mailbox provider (MBP) or ISP that is bouncing. This will give you areas to investigate further. 

Spam complaint rate

Once your email reaches the inbox, the next step is to ensure it doesn’t get marked as spam. The spam complaint rate measures how often recipients actively mark your email as spam. Note this doesn’t measure how often your email lands in the spam folder but only how often a recipient actively marks your emails as spam.

  • Spam complaints / email sends = spam complaint rate

Benchmark: <0.01%

How to improve? Conduct regular list cleaning. Don’t give subscribers an excuse to flag you. Use segments to avoid sending tons of emails to inactive subscribers. This is one of the fastest ways to increase your spam complaint rate (not good).


Open Rate

Once your email reaches a subscribers inbox, and isn’t marked as spam, the next step is to get your subscriber to open the email. Open rate measures how often that happens.

  • Email opens / email sends = email open rate

Benchmark: >30% (excluding MPP)

Note: Open rates have become more difficult to measure since Apple implemented Mail Privacy Protection (MPP) a privacy policy change which automatically marks emails as opened which will inflate open rate numbers.

How to improve? Open rates are a measure of the success of your email subject lines. You should be consistently A/B testing subject lines to maximize open rates. Boring subject lines won't get opened. 

Unsubscribe Rate

While it’s great to get someone to open your email, if they only open the email to unsubscribe that's clearly not a good thing. Unsubscribe rates measure the percent of recipients who actively unsubscribe from your emails. You should expect some normal level of unsubscribes. If your unsubscribe rate is too low it might actually be a sign that you’re sending too few emails. Higher than benchmark unsubscribe rates, however, are a sign that something is wrong. 

  • Number of recipients who unsubscribe / total number of delivered emails = email unsubscribe rate

Benchmark: <0.3%

How to improve? Clean and segment your list. High unsubscribe rates are likely a sign that you need to do a better job cleaning and segmenting your list. You are likely sending too many emails to those who aren’t engaged with your emails. Some marketers will see high unsubscribe rates and immediately move to send fewer emails. We think you should focus your efforts on better segmentation rather than first looking to reduce the number of emails you send. A high unsubscribe rate would be 1% which means that 99% of your list is still getting some sort of value from your emails. 

Click Rate & CTR: Click Through Rate

Once someone has opened your email, the next step is to get them to click through to your website. The click rate and click through rate are two slightly different ways to measure the same thing: the number of people who click on a link from an email and visit your website. 

  • Click rate = email clicks / emails delivered
  • Click Through Rate (CTR) = email clicks / emails opened

Benchmark: Click rate >2%, CTR >6%

How to improve? Have a single, clear call to action. The worst thing you can do is confuse an email recipient with tons of different calls to action. Each email should have one clear call to action. Yes, you can have other links in your email (products you might like etc.), but every email should have one single, big,  juicy ‘click here’ button. The color should stand out and the design of the email should be simple. It should be clear on a single glance where the CTA button is. 

Email conversion Rate

Once a recipient has clicked through your email to your website, the next step is to convert them into a customer. The email conversion rate is the end measure of many steps in your email funnel. 

  • Purchases attributed to email / email recipients = email conversion rate

Benchmark: >1.5%

Note: For attribution we recommend using Google Analytics Last Non-Direct Click attribution. If you use the attribution metrics from your ESP, you will likely be over attributing conversions to email. 

How to improve? Since this is the last step in a many step funnel the first job is to check that all of the previous metrics are in line with benchmarks. Often low conversion rates will be caused by some breakage earlier in the funnel. If all of those metrics look good and the email conversion rate is still low, then the issue likely lies with your website. We will cover conversion rate optimization (CRO) in a future guide, but this is where we recommend spending your time. There are likely quick wins you can implement on your website to optimize the conversion rate. 

Incrementality of Email

This last metric is designed to measure the incrementality of your email program or put another way how valuable is your email program? Incrementality is notoriously difficult to estimate. It attempts to estimate the value of the channel by asking how many sales would have gone to another channel if this channel had not been there. 

For this calculation, we must give a hat tip to Ben Yahalom from True Classic Tees who mentioned it on the Limited Supply Podcast. (Read our guide on True Classic)

  • LTV of customer subscribed to your email list - LTV of customer not subscribed to your email list = Incremental value of email

So if the LTV of a customer on your email list is $140 and the LTV of a customer not on your email list is $120, then $20 is the incremental value of getting someone to subscribe to your email list.

The methodology isn’t perfect because more engaged, ‘better’ customers are more likely to subscribe to your email list and thus spend more, but it’s one of the best methodologies we’ve found to estimate the incrementality of your email.

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