What you should measure in email marketing

Let’s start this module with a list of the items you should be tracking in your email marketing.

Some metrics are very straight forward, but there are others we need to discuss in more details, we’ll do that in the following lessons.

I’ve categorized these metrics by:

  • List
  • Campaign
  • Subscriber


List Growth

Measuring list growth is not exactly looking at how many subscribers you have any given month, but the rate at how your email list is growing.

This is one of the metrics we’ll explore in more details in the following lessons, so I’ll leave there.


Unsubscribes also have its own lesson in this module, but I’ll say this:

The reason you need to track unsubscribes at the list level is to identify sudden changes. For example, if you have an average monthly churn rate of 20% and then it suddenly goes to 35%, there is something you need to investigate in your strategy.



Delivery rate

The delivery rate is key because before you can get any opens and clicks, your emails need to be delivered. Many people make the mistake to look only at open rates when the problem could easily be deliverability.

The delivery rate is the percentage of emails sent that actually made it to the inbox.

Formula: Emails sent – Bounces (soft and hard) = Number of emails delivered / emails sent


Open rate

Open rate is one of the most popular metrics in email marketing for obvious reasons, but there are some problems we need to discuss. For this reason, I’ve create a separate lesson.



The Click-Through Rate (CTR) is something that is included in campaigns reports. All ESPs do this, so there is no need to do anything to get to that number.

Let’s see that the formula is anyways, so we can understand how it’s calculated.

CTR is the percentage of the subscribers in your list that clicked in any of the links in your campaign.

Formula: Clicks / Delivered emails

(Mailchimp takes the number of emails delivered, while Aweber and GetResponse takes the number of emails sent)

Click-to-open rate

I believe CTOR is a better metric than CTR, because it measures the clicks against opens. In other words, of the subscribers that opened the email, how many clicked on a link.

ESPs do not calculate this for you, so it’s one of those metrics you will have to deal with yourself.

Formula: Clicks / Emails opened


Bounce rate

Bounce rate is the percentage of the emails that didn’t makes it to the inbox.

There are 2 kinds of bounces (we covered this in the course):

  • Soft bounces: A temporary issue like a full inbox or a server is down
  • Hard bounces: A permanent issue like a typo in the address or a closed account

Use it as an indicator. A drastic change in your bounce rate can represent a potential problem.

This is calculated by your ESP on every campaign.



Unsubscribes should also be watched on each campaign. A higher than average unsubscribe rate in one specific campaign might mean that you made a lot of people upset.

We’ll talk about this in detail in one of the other lessons.



Aweber calls it “Complaints” and Mailchimp calls it “Abuse Reports.” It is provided by your ESP on each campaign report. No need to figure out anything on your own.

Aweber says that your complaint rate should always be below .1% (one-tenth of one percent).

Formula: Complaints / Emails sent


Conversion rate should be the most important metric for your business. It represents the percentage of people that click on your campaign link and took a desired action, like a purchase.

You’re probably thinking that your ESP is not capable of providing this kind of data, but you’re wrong.

Aweber actually works the same way as Google Analytics “Goal Tracking.” You provide a success URL as a goal and install a piece of code on your site. You even have the option to add a monetary value to track revenue.

Conversion - Aweber

Mailchimp can also track goals with its own plugin called… yes, “Goals.”

And, as we already saw, you can also track conversions with Google Analytics Goal Tracking.

Conversion - Analytics

Formula: Desired action (for example: Sale) / Number of clicks


Subscriber Value

We have an entire lesson dedicated to this metric later in this module.