There's a lot to say when it comes to how to do email marketing well. We could talk for days about the most critical components of an optimized email, common email marketing mistakes you might be making, and examples of brilliant email marketing that will inspire you. But at the end of the day, it doesn't matter how optimized your emails are if you can't see the results of your efforts -- not to mention measure whether email is helping you hit your goals.
So before sending your next email, pause for a few minutes and ask yourself: What is the goal of my email marketing? Is it to grow my subscriber database? Generate more leads? To convert more existing leads into customers?
Whatever you decide your goal is (and you can have more than one), the next thing you need to do is figure out which metrics you'll need to track in order to determine how you're progressing toward that goal.
Let's take a look at the metrics you should be paying attention to in your email marketing efforts. We'll start with the metrics every email marketer should be tracking, and then we'll take a look at how to tie certain metrics to your specific goals.
6 Email Metrics Every Marketer Should Include in Their Email Report
1) Clickthrough Rate
- What It Is: The percentage of email recipients who clicked on one or more links contained in a given email.
- How to Calculate It: (Total clicks OR unique clicks ÷ Number of delivered emails) * 100
- Example: 500 total clicks ÷ 10,000 delivered emails * 100 = 5% clickthrough rate
(Using either total clicks or unique clicks in the calculation above works, as long as you use the same approach consistently.)
Clickthrough rate (CTR) is likely the first answer you'll get when you ask an email marketer what metrics they track. It's what I like to call the "day-to-day" email marketing metric, because it lets you easily calculate performance for every individual email you send. From there, you can track how your CTR changes over time.
CTR is also frequently used for determining the results of A/B tests, as these tests are often designed with the intention of finding new ways to get more clicks in your emails. Clickthrough rate is a very important metric for all email marketers to be tracking, as it gives you direct insight into how many people on your list are engaging with your content and interested in learning more about your brand or your offer. Read this blog post to learn what a "good" clickthrough rate is, according to industry benchmarks.
(HubSpot customers: Click here to learn how to easily set up click tracking in your emails using HubSpot.)
2) Conversion Rate
- What It Is: The percentage of email recipients who clicked on a link within an email and completed a desired action, such as filling out a lead generation form or purchasing a product.
- How to Calculate It: (Number of people who completed the desired action ÷ Number of total emails delivered) * 100
- Example: 400 people who completed the desired action ÷ 10,000 total email delivered * 100 = 4% conversion rate
After an email recipient has clicked through on your email, the next goal is typically to get them to convert on your offer -- in other words, to take the action that your email has asked them to take. So if you're sending an email to offer your audience the chance to download, say, a free ebook, you'd consider anyone who actually downloads that ebook to be a conversion.
Because your definition of a conversion is directly tied to the call-to-action in your email, and your call-to-action should be directly tied to the overall goal of your email marketing, conversion rate is one of the most important metrics for determining the extent to which you're achieving your goals. (We'll discuss more specific goal-related metrics later.)
In order to measure conversion rate on your emails, you'll need to integrate your email platform and your web analytics. You can do this by creating unique tracking URLs for your email links that identify the source of the click as coming from a specific email campaign.
3) Bounce Rate
- What It Is: The percentage of your total emails sent that could not be successfully delivered to the recipient's inbox.
- How to Calculate It: (Total number of bounced emails ÷ Number of emails sent) * 100
- Example: 75 bounced emails ÷ 10,000 total emails sent * 100 = 0.75% bounce rate
There are two kinds of bounces to track: “hard” bounces and “soft” bounces.
Soft bounces are the result of a temporary problem with a valid email address, such as a full inbox or a problem with the recipient’s server. The recipient’s server may hold these emails for delivery once the problem clears up, or you may try re-sending your email message to soft bounces.
Hard bounces are the result of an invalid, closed, or non-existent email address, and these emails will never be successfully delivered. You should immediately remove hard bounce addresses from your email list, because internet service providers (ISPs) use bounce rates as one of the key factors to determine an email sender’s reputation. Having too many hard bounces can make your company look like a spammer in the eyes of an ISP. (Read this blog post to learn more about the difference between hard and soft bounces.)
4) List Growth Rate
- What It Is: The rate at which your email list is growing.
- How to Calculate It: ([(Number of new subscribers) minus (Number of unsubscribes + email/spam complaints)] ÷ Total number of email addresses on your list]) * 100
- Example: (500 new subscribers - 100 unsubscribes and email/spam complaints) ÷ 10,000 email addresses on the list * 100 = 4% list growth rate
Aside from the call-to-action metrics (CTR, conversion rates), you'll also want to be keeping tabs on your list growth and loss. Of course, you should be aiming to grow your list in order to extend your reach, expand your audience, and position yourself as an industry thought leader. But believe it or not, there's a natural decay of your email marketing list, and it expires by about 22.5% every year -- which means that it's more important than ever to pay attention to growing your subscriber list and keeping it at a healthy size.
5) Email Sharing/Forwarding Rate
- What It Is: The percentage of email recipients who clicked on a “share this” button to post email content to a social network, and/or who clicked on a “forward to a friend” button.
- How to Calculate It: (Number of clicks on a share and/or forward button ÷ Number of total delivered emails) * 100
- Example: 100 clicks on a share/forward button ÷ 10,000 total delivered emails * 100 = 1% email sharing/forwarding rate
The rate at which your email recipients forward or share your email with others may not seem all that significant, but it's arguably one of the most important metrics you should be tracking.
Why? Because this is how you generate new contacts. The folks on your email list are already in your database. So while conversion is still a primary focus, this doesn't help you attract new leads. Encourage your readers to pass along your email to a friend or colleague if they found the content useful, and start tracking how many new people you can add to your database this way. (Read this blog post for tips on getting people to forward your emails.)
Keep a careful eye on your sharing rates to discover which types of articles and offers tend to get shared the most, and use that insight when you plan email campaigns in the future.
6) Overall ROI
- What It Is: The overall return on investment for your email campaigns. In other words, total revenue divided by total spend.
- How to Calculate It: [($ in additional sales made minus $ invested in the campaign) ÷ $ invested in the campaign] * 100
- Example: ($1,000 in additional sales - $100 invested in the campaign / $100 invested in the campaign) * 100 = a 900% return on investment for the campaign
(Note: This is the most basic formula to calculate ROI — but there are several ways to approach calculating the ROI of your email campaigns. Depending on your type of business, you might prefer a different one.)
As with every marketing channel, you should be able to determine the overall ROI of your email marketing. If you haven't yet, set up an SLA system whereby you assign different values to various types of leads based on their likelihood to generate revenue for your company.
How many of each of these types of leads did you generate via email marketing? How does this translate to potential revenue? Actual revenue? These are the types of metrics that will help you show your boss and your sales team how valuable email marketing is as a channel that drives real, tangible results.
How to Know Which Email Metrics to Track, Based on Your Goals
The goal of your email marketing may be very different from the goals of another company like yours, and may even vary within your own company over time. But again, it's crucial that you determine exactly what it is you're looking to achieve with your email marketing before you begin (or continue) to send and measure your emails.
Here's how you can align your specific goal with key metrics.
Subscriber List Growth Rate
If your focus is on growing the top of your funnel -- attracting more visitors to your site, signing up more blog subscribers, getting more people to use your free tools, that kind of thing -- your goal will probably be growing your subscriber list. Your emails will likely contain calls-to-action such as "Subscribe to Our Blog" or "Join Our Weekly Email List." So of course, the most important metric you should be tracking for this goal is the growth rate of your subscriber list. (Read this blog post for more detailed tips on how to grow your subscriber list.)
Just as you want to track and grow your subscribers, it's also important to keep an eye on your unengaged subscribers -- and consider removing them from your list altogether. Why? Because sending emails to people who aren't engaged with your emails (called "graymail") can hurt the deliverability of your email overall. Email clients might get tipped off by low engagement rates and deliver email from known-graymail senders straight to recipients' "junk" folders, meaning your emails will technically get sent and delivered, but won't necessarily be seen.
Here at HubSpot, we deliberately unsubscribed 250,000 people from HubSpot's Marketing Blog, which included people who had opted in to receive emails about new content we published on the blog. This subscriber purge brought our total subscriber count from 550,000 down to 300,000. Read this blog post to learn more about why and how we purged our subscriber list, and why you might consider doing the same.
Number of New (or Total) Leads Generated
Maybe instead of focusing on subscribers, you'd like to work on growing lead generation. If this is the case, you should be sending emails that offer lead generation content -- in other words, content that requires the viewer to fill out a lead capture form in order to access it.
If the goal of your email marketing is lead gen, you should be tracking how many leads you're capturing every day, and every month. You can decide to focus on all leads generated, or only new ones added to your database, depending on your priorities.
Lead-to-Customer Conversion Rate
Finally, let's say you want to focus more toward the middle/bottom of your marketing funnel, and convert more of your existing leads into customers. If this is your goal, the emails you're sending will likely provide content more closely related to your business and your product or service. Your calls-to-action may include "Get a demo," "Watch a Video of Our Product in Action," or "Start a Free Trial." If this is your goal, you should be tracking changes in your lead-to-customer conversion rate.
As obvious as this all seems, you'd be surprised how many email marketers determine their goals and then don't bother to track their progress against them. Make sure that you're able to track how closely you're trending toward your goal at any point during the month, and that you're looking carefully at any changes in these metrics month over month.
Unreliable Email Marketing Metrics
It's worth mentioning that there are also a couple of email marketing metrics that really aren't worth tracking closely.
What It Is: The percentage of email recipients who open a given email.
Most email marketers are still bent over backwards trying to optimize their subject lines for higher open rates. While this can have a positive impact -- and more opens are a great thing -- they really should be focused on optimizing their clickthrough rates, instead.
The fact of the matter is that open rate is actually a very misleading metric for a few reasons. Most importantly, an email is only counted as "opened" if the recipient also receives the images embedded in that message. And a large percentage of your email users likely have image-blocking enabled on their email client. This means that even if they open the email, they won’t be included in your open rate, making it an inaccurate and unreliable metric for marketers, as it underreports on your true numbers.
Note: You can get some value out of open rate as a metric if you use it as a comparative metric. For instance, if you compare the open rates of this week's email send to last week's email send (both to the same lists) it might give you some insight since the variables are somewhat controlled.
As with open rate, the unsubscribe rate isn’t a reliable picture of the health of your email list. Many subscribers who are tired of receiving email messages from your brand won’t bother to go through the formal unsubscribe process. They’ll just stop opening, reading, and clicking on your email messages.
That's why it's much more effective to measure subscriber engagement by clickthrough rates and conversion rates. From there, you can keep an eye out on unengaged subscribers so you can consider removing them at some point, like we went over earlier. Checking your monthly unsubscribe rate is helpful for calculating your overall list growth rate, though, so do keep an eye on it every once in a while.
The bottom line? Be smart about which metrics you're tracking, and make sure you're able to effectively measure your individual email performance, the health of your email list, and your progress toward your overarching goals. As long as you're able to determine each of those, you're on the right track for more effective email marketing.
Editor's Note: This post was originally published in March 2014 and has been updated for accuracy and comprehensiveness.