6 KPIs that will help you gauge your email campaign's success

There's an old saying in the business world: "What gets measured gets managed." 

That means that you'll have an easier time understanding how well a project is working if you have quantifiable metrics to tell you exactly how it's going. 

Let's say you have a goal to lose weight. You'd track what you eat, how often you work out, and how many pounds you weigh on a daily or weekly basis. 

That's the only way you'll know if you're getting closer to your goal. 

The same line of thinking applies to an email campaign. If you don't have goals in mind when you start the campaign, it's going to be much harder (and pretty much impossible) to gauge how well it's performing. 

In this post, we're going to look at some metrics or key performance indicators (KPI) you can look at to better understand how well your email campaign is doing. 

The role of KPI in your email campaign 

Before we discuss the specific KPI you'll want to look out for to gauge your campaign's success, a note about overall email campaign planning: you'll want to write out your email campaign plan before you start. That plan should include: 

  • Your campaign's goal
  • Any audience research you may have
  • The KPI you'll use to measure your campaign's success (more on that below) 
  • The overarching strategy you'll use to execute the campaign
  • The specific tactics you'll use to carry out the campaign
  • The timeline for measuring the campaign's success

Without a concrete plan in place before you start, you'll have trouble staying organized and on target. You can always adjust the campaign once you get started - flexibility is often critical in executing a successful campaign. But you need some kind of guidelines in place so you know where you're going.

Look at your plan as a roadmap, and if the plan is a roadmap, your KPI function as specific directions that help you understand if you're going the right way. 

Open rate

An email is only effective if someone reads it. One of the easiest to calculate KPI you can use to determine your email campaign's success is an email's open rate. 

Some platforms will do the math for you, but if not, here's how you figure it out: divide the number of opens by the total number sent. There you have your open rate.

Open rate isn't a perfect statistic by any means. Opening an email is the most basic level of engagement, and it won't tell you how well your content was received once the intended recipient viewed the email. 

But it can tell you a few very valuable things, including: 

  • Among the people who have signed up for your email list, who is invested enough to actually take the next step in investigating what you have to say after you've reached out to them? You may be ending up in people's spam folder if open rates are notoriously low. 
  • How effective are your email subject lines? A subject line has to capture the recipient's attention. Without an engaging subject, you're much more likely to stay unopened or deleted. 
  • Who wants to hear more about what you have to say? 

Again, your open rate is hardly the be-all-end-all in terms of KPI measuring an email campaign's success or failure. But it's a good start, and it's one you'll want to factor into your analysis of the campaign. 


Some platforms will let you know how many people have forwarded your email to others, and how many people they forwarded it to. This is a valuable metric because it shows how well your messaging is resonating with your core audience. 

When someone forwards your email, they're saying they want to be an evangelist of your message. They like what they're hearing and they want other people to be exposed to it. This is a good thing, and it's how you create new audience members. In all likelihood, the original person forwarding your email is sending it to like-minded people. They're doing the work of marketing your campaign for you. 

As an engagement KPI, forwards tell you who among your audience likes what they're hearing so much that they want others to get in on it as well. Conversely, if you're not seeing a lot of people forward your offers or information, it could mean you need to improve the value you're offering. 

Subscriber list signups

Just like forwards, one goal of your email campaign may be to understand how many new signups to your subscriber list you see. This goes beyond evaluating the engagement with your existing list. It tells you how many new people you're reaching with your campaign. 

You may reach these people via email forwards or through signups from your website while you're conducting your campaign. Either way, you'll want to keep an eye on how many new audience members you bring in while the campaign is ongoing. 

Why is this important? It tells you how scalable your audience really is. If your subscriber list stays stagnant while you run an email campaign, it could mean that your offer needs improvement. It also means you could need better email marketing as well. Perhaps the copy in your emails isn't as persuasive as it could be. 

Increasing your subscriber count shouldn't be the primary goal of any email campaign - after all, much of your efforts dedicated to adding subscribers will occur outside the campaign, via your website or social media channels. But it can be one KPI in a collection of metrics you use to evaluate effectiveness. 


While measuring the number of new subscribers will be useful as KPI, even more useful is looking at how many people are unsubscribing from your list. 

Remember: anyone unsubscribing from your list is someone who was already a part of your audience and is now asking to be removed from that group. That means that whatever marketing or engagement efforts you implemented weren't working on them. 

Certainly, this can be a tough pill to swallow. And sometimes, there's nothing you can do: for example, if you're a local merchant and one of your email subscribers moves away, they may have no more need for your offering through no fault of your own. 

But many times you can use an unsubscribe count to determine whether your messaging, copy, or overall campaign approach needs tweaking. If one email sees an above-average number of unsubscribes, that may be an indicator that you missed the mark with that piece of content. Maybe the internal copy or subject line requires more thought. 

Evaluating how many people unsubscribed from your list during the campaign can be rough because ultimately it's a piece of negative feedback. But look at this KPI as a teachable moment: it provides actionable feedback you can use to strengthen your campaign. 

Clicked links on campaign emails

This is one of the most valuable KPIs you'll have at your disposal during an email campaign. When you include links within your email, you'll want to examine how many people are clicking which links. 

This is true no matter what kind of email campaign you're running. As long as you include some kind of links within the email, you'll want to see how many people are clicking on which ones. 

There's so much valuable information you can glean from this data. If you're offering discounts or sales, you'll see how strong your offering is by determining how many people are "biting" on your offer. If you're simply offering links to other pieces of content relevant to your audience, you'll find out which ones they find the most interesting. You can then laser-focus your next email on these types of content pieces, figuring out exactly what your audience finds useful. 

Your open rate will tell you how many people are taking the first step of engagement with your brand's email campaign. Looking at the clicked links gives you the next level of engagement. It tells you: 

  • Who's interested in the information/deal you're offering
  • What particular kind of information/deal are they interested in, if you have more than one link 

Anyone not using clicked links metrics as a way to adapt their content offering is missing a big opportunity. 

Purchases from emails

If you're not offering sales or discounts in your emails, this item may not apply to you. But if you are, that means one of your email campaign's goals is to drive sales. That means that evaluating the number of sales you make directly from your campaign's emails is a can't-miss KPI to include in your overall metrics. 

You can do this by looking at who clicked through on the links to your sales page and determining how many of them lead to actual sales once they moved to the checkout phase. 

If you're not selling a product specifically, but promoting some other kind of "call to action" like downloading an eBook or some other kind of lead magnet, you can substitute that metric for sales instead.

Either way, understanding who's taking action on the specific CTA you include within the email is vital to understanding your campaign's success.

Keep in mind that all of these alone won't tell you your email campaign's story. Looking at them together will give you a top-down, holistic view of how well your campaign is hitting its intended mark. 

If you're interested in engaging your audience more effectively, Sendlio is the partner for you.  Book a demo today to see how we can help you convert more leads to customers. 


Want more content like this?

Drop your email in the form to subscribe and receive more content like this directly in your inbox!

Signup for Our Newsletter

Don't worry. We won't share your email address or send spam. Unsubscribe at any time.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram