Nine key email marketing metrics and what they tell you about your campaigns

To judge the effectiveness of a marketing campaign and track email performance, marketers often look at conversion. However, there are numerous other specific metrics that all feed into your conversion rate and thus must be measured in your email marketing campaigns.

By observing these metrics and comparing them to email marketing benchmarks and your business’s specific key performance indicators (KPIs), you can see which areas are performing well and which need improvement.

In this article, we’ll explain nine of the most important email marketing metrics to measure, what factors impact these email metrics and what they can tell you about your email marketing strategy.

Bounce rate

Your email bounce rate tells you the percentage of your emails that never made it to the recipient’s inbox. There are two types of bounce rates: hard bounces and soft bounces.

Hard bounces can mean your email didn’t make it past a subscriber’s spam filter or that the email address is fake or inactive. This type of bounce is permanent and sends a major red flag to internet service providers (ISPs). Fortunately, most email marketing automation tools will remove bounced email addresses from future sends.

Soft bounces can mean your email didn’t make it to the inbox because it’s full or there’s a file in your email that’s too large. This type of bounce is temporary and many email service providers will continue to try and deliver your email over the following days.

Bounces are inevitable, especially as your list grows and the number of emails you send increases. Even though soft bounces aren’t always under your control, a high bounce rate affects your sender reputation and domain health, which in turn affects your email deliverability rate and email campaign metrics.

To avoid this, practice good email list hygiene by removing inactive subscribers from your email list and using a double opt-in (i.e. where subscribers must open an email from you and click a button to confirm their email address before officially joining your list).

Deliverability rate

Your deliverability rate is the percentage of emails you sent that made it to your subscribers’ inbox. Deliverability rate does not include the emails that landed in the spam folder (that’s delivery rate).

There are a variety of factors that influence this email metric, including keeping an eye on your sender reputation and making sure your domain isn’t on any block lists. The easiest way to ensure a high deliverability rate is to only send marketing emails to people who have opted into your list.

Open rate

Your email open rate is the percentage of emails delivered that were then opened. It only includes unique opens rather than repeat opens. It’s impacted by three things: your deliverability rate, your subject line and preview text and your time of sending.

If your open rate seems low, first check your email deliverability. If that looks normal, it’s most likely an unengaging subject line or the fact that you’re sending at the wrong time of day (i.e. when your subscribers are least active). Consider A/B testing these two things, as well as any other component of your emails you’d like to optimize, such as promotions or calls to action (CTAs).

Spam complaint rate

Your spam complaint rate is the number of people who reported your emails as spam out of how many were delivered to subscribers’ inboxes. Similar to bounces, spam complaints are very detrimental to your email deliverability and an important email campaign metrics to keep an eye on.

There are many ways to avoid this, primarily by only sending emails to people who have opted in and sending content that’s relevant to your target audience and audience segments.

Additionally, placing a clearly marked unsubscribe link in your emails can help mitigate spam complaints from annoyed subscribers. Visible unsubscribe links are also required by law according to the CAN-SPAM Act and GPDR, so make sure to include them to remain compliant.

Click-through rate

Click-through rate (CTR) is the number of clicks l out of the total number of emails delivered. This email marketing metric helps you measure your email’s performance as it relates to engagement.

It’s possible for your CTR to be impacted by how many people open your emails, but that’s not always the case. For example, an email campaign can have a very high open rate and a low or non-existent CTR. That would mean your subject line was attention-grabbing, but your email content didn’t measure up.

To improve your click rate, make sure your emails are optimized and formatted correctly for mobile devices.

CTR is not to be confused with click-to-open rate (CTOR). CTOR is the percentage of those who opened your email who also clicked on it. CTR simply tells you how many people clicked your emails out of how many you sent.

List growth rate

List growth rate tells you how quickly your list is growing (or not growing) over a certain period. To measure list growth rate accurately, take the number of new email subscribers over time minus the number of unsubscribes and spam complaints in the same time period. Divide by the total number of subscribers to get the final number.

A dip or lag in this email metric can mean several things, including a high unsubscribe rate.

If your unsubscribe rate hasn’t increased, consider checking your lead generation offers. Customer needs and desires change, so what once might have been an attractive freebie or giveaway in exchange for one’s email address may no longer be as enticing.

Conversion rate

Your conversion rate is the percentage of people who have taken a desired action. This could be making a purchase, or simply clicking the “Read more” button on a blog post snippet. It’s up to you and your business what you’ll record as a conversion.

Creating a good email content plan with relevant, on-brand messaging that resonates with subscribers is one way to ensure high conversion rates. Including a compelling offer in your promotional emails and including a single, prominent call-to-action (CTA) button are others.

Revenue per subscriber

Revenue per subscriber tells you how much revenue, on average, is generated from a single subscriber. Since return on investment is an important goal, this metric helps you understand whether email marketing is a high-yielding channel for your business.

This email metric can also help marketing teams make a business case for their email marketing efforts, even if other metrics are below your benchmarks.

In ecommerce, measuring revenue per subscriber can help you gauge which products you should run promotional emails campaigns for. Ifyour email engagement and conversion rates are high but you want a higher ROI for your promotional email efforts, you could consider promoting products with a higher average order value (AOV). Keep in mind that conversion rates might decrease if you do this, but your overall revenue may increase.

Unsubscribe rate

Your unsubscribe rate is the percentage of people that remove themselves from your subscriber list in a given period. A high unsubscribe rate usually comes down to your email content.

Setting clear expectations on your landing page or email sign-up form and sending a welcome email (or series of welcome emails) can help to keep your unsubscribe rate low.

List segmentation can also help. This is when you group your subscribers into segments based on various factors, including the type of content they want to receive or are most likely to find engaging. Creating relevant, valuable content for each list will take more time and effort, but parts of the process can be automated via email marketing platforms.

No matter how you execute it, segmentation can drastically reduce unsubscribes and increase conversion rates.

Final thoughts

Being data-driven isn’t helpful if your email marketing strategy is dictated by irrelevant metrics. The same can be said for your overall digital marketing strategy.

The nine email marketing metrics above provide a helpful starting point to gauge the success of your email marketing efforts.

Crafting your email marketing strategy based on data from your email marketing platform’s dashboard is a great foundation, but don’t be afraid to experiment and test new things with your audience.