The Top 5 KPIs That Determine Your Email Marketing ROI (and How to Improve Them)

Key performance indicators (KPI’s) are an important part of any business. Return on investment (ROI) is one of the top ways to the success of any business. If you invest time, effort, and finances into anything; you need to calculate your return. The need for investments that make sense is true in every aspect of your marketing—including email.

Unfortunately, email gets a bad rap. Every year someone says it’s dead and most small businesses don’t even try the channel. Those that do give it an honest go aren’t very good at calculating how much revenue, loyalty, or awareness that email actually generates.

We hope to change that, today!

You see, there are tons of KPI’s specific to your email marketing. So many, in fact, that it can be easy to have a lot of facts and stats without actually knowing anything.

Depending on your goals, certain metrics can be more telling of your success (or failures) than others. In this post, we hope to show you which metrics are best (in a broad sense) for determining the ROI of your email marketing efforts.

Here we go.

What (Exactly) Did You Invest?

We mentioned a few ways that you can invest: time, effort, and cold hard cash. Since the title is ROI, your mind likely went immediately to money. That’s ok. It all comes down to that anyway.

You can’t adequately track ROI until you figure out the investment made.

Your email service provider costs a monthly fee. Collecting those email addresses via Facebook and LinkedIn ads will also give you a cost per lead. After outsourcing your content marketing efforts and paying a copywriter to whip up that super sales email, all of it adds up to a decent (usually monthly) investment.

If you do any of this yourself, put in what your time is worth. Really try to get an accurate number, it will help.

Impressive Stat: According to research from the Direct Marketing Association, 60% of consumers have made a purchase due to an email marketing campaign.

KPI #1: Conversion Rate (from a Campaign)

This item on the list gets the Captain Obvious award, but we are talking about ROI here. The quickest way to get a loose number is to see what percentage of subscribers in your campaigns convert into customers.

If you are in the B2B/SaaS/Consulting world, it’s likely that you have a drip campaign to nurture your leads over time. If so, you will want to take a longer view of your  conversion rate, and you might want to consider treating a “qualified lead” or “sales appointment” as a conversion, rather than a sale. This will help you optimize for more appointments, at least until you have more data to track all the way to revenue and deal size.

In Drip, you can easily view stats on your conversion rate for any given campaign.

Simply navigate to any campaign and select the date range you would like to view. Your stats will update automatically, including the cohort conversion rate–the percentage of subscribers that converted during that date range (hover to zoom in):

email marketing roi image

KPI #2: Email List Growth

Our second choice is only for those who are actively trying to increase their list through advertising. If you are cold-calling and emailing leads and putting them through cadences, your list is growing as fast as you can add people.

If you’re advertising, this number represents the first conversion a person has with your brand. Each person putting in their email is moving from unaware to a lead that is ready to be nurtured.

Where to Look: If you are getting an ad/offer in front of a decent amount of targeted people, but sign ups aren’t matching up, there may be some issues. The most common mistake is an ad that takes your lead to a page that looks nothing like the original ad. You’ll break the experience and lose trust.

Fixing the Problems: 1.) Make sure your offer is what a super-targeted audience would love to have and 2.) make sure your sign-up page looks exactly like the ad they clicked on. Doing so should give you a bump up in subs.

Bonus Tip: Since this is the first interaction with your brand, you’ll want each person to fit at least a general picture of your buyer personas. It will help with conversion rates down your email sales funnel.

KPI #3: Subscriber Engagement

This item on the list includes a couple of different KPI’s that could affect your ROI over time. Namely those indicators are bounce rate and open rate. These factors are especially important if you are doing a mix of phone and email marketing.

Example: Your sales reps are heavily involved in both the email campaigns and directly calling prospects. The list is full of leads that haven’t opened an email in six months, leaving reps trying to move a lead that is wasting their time.

If this sounds like your list, it’s time to clean house.

Where to Look: Any ESP worth their price will be able to give you the KPI’s that matter. Look for the bounce rate (the addresses that are fake/invalid) and the open rate (usually around 30%). On the open rate, it’s important to segment those who are opening an email now and again and those who just aren’t engaged at all.

If your email is bouncing (because the address was fake or invalid), drop ‘em. If they haven’t opened one of your emails in a while, try to let them know you’ll be cleaning them off of your list (an effective tactic at times).

Bonus Tip: If your open rate is consistently low, try writing more casual email copy that’s easy for people to read. We’ve seen casual, conversational email copy outperform more formal styles over and over again, even in B2B industries.

Here are some good books on classic direct-response advertising to improve your copy:

KPI #4: Click-Through Rate

Ok, now we’re getting into the good stuff. Your list is growing, great. Subscribers actually open emails, good for you. That said, unless your email readers are getting to the next stage of your funnel (and eventually buying) there is no ROI.

Click-through rate is the percentage of readers that open the email who click the intended call-to-action (CTA) on the inside. Keep in mind that this doesn’t have to be a direct sales-related offer. Some of the CTA’s include:

·      Download a report that moves them to a different portion of the sales funnel.

·      Sign up for a webinar that will demonstrate your product or offer industry related help.

·      It could be as simple as clicking to read the latest blog post (nurture them, right?).

Bottom Line: If they are reading the email and not clicking, you’ll have to figure out why. It could be anything from the copywriting or the offer itself. Make sure that each CTA speaks to your audience. If readers never engage, you could even give them a call and ask for brutal honesty.

Here’s what your open rate and CTR metrics look like in Drip for individual broadcasts (hover to zoom in):

analytics 2

KPI #5: Reply Rate

This one is a wildcard. While reply rate doesn’t directly translate to revenue, your reply rate can indicate the overall health of your email list (and your relationship with readers).

Now, if you are a B2C clothing brand, reply rate might not be a great KPI. But if you’re a professional blogger, consultant, agency owner, or SaaS startup working more intimately with your leads, you want to know your reply rate. Try sending a short email that asks your list to hit “reply”–and see how many responses you get.

Here’s some swipe copy for your experiment:

Hi {{ subscriber.first_name | default: “there” }},

I’m putting together some more content about ** TOPIC ** to help you ** BENEFIT **.

I’m just curious, what’s your #1 challenge right now with ** TOPIC **?

Hit reply and let me know. I’ll personally read and reply to every email.


Make sense? Good.

In Drip, you can turn on reply tracking under Settings > Account when you click “enable email reply tracking.” After that point, you will see your reply rate for every broadcast email.

Bonus Tip: you can also trigger Workflows when leads reply to an email. This is useful if even you only want to tag subscribers “replied to an email.” In the future, you can send broadcasts ONLY to subscribers who have previously replied to emails, to ask for product ideas, survey responses, and testimonials. More often than not, readers who reply are the ones who care the most and are more likely to be your super fans.

reply trigger

Now that we’ve covered the top five KPIs you should be tracking, let’s talk about a few ways to improve your metrics (and your ROI on email marketing).

Put Good In, Get Good Out

It’s not just for your diet anymore. The better your leads and subscribers that enter your email marketing campaign, the better your conversions will ultimately be. If your brand can do a better job of identifying the traits of common and ideal buyers, you can find leads that share those traits, making them more likely to buy.

Bonus Resource: We just described using buyer personas in a couple of sentences, here’s a more in-depth guide.

Segment, Segment, Segment

If you only have one basic line for all your leads to go through, it could be throwing some potential customers off. Depending on the number of products you have, the number of target industries and other factors, you may need to segment the audience. Give custom paths to any subset of your leads that may need it.


Personalizing emails to a larger audience has never been easier or more necessary. The truth is that people are pickier and they can spot a generic offer from miles away. Not to beat an old drum, but how personal you can get depends on your size. Segmentation will majorly help with making things more meaningful.

Time to Get Calculating

Ok! It’s time to start thinking about email in terms of profit. If you aren’t using your list to generate revenue (either directly or indirectly), it’s time you start.

Let us know in the comments what your plans are to increase the ROI of your email marketing efforts.