If you're doing email marketing, you naturally want to know how successful your activities are. There are some obvious metrics, but they are not always absolutely meaningful. In this article, I'll explain what you should pay attention to.

In previous parts of this article series, we already talked about the right concept, how to gain more readers and also legal issues. In two other articles here at Raidboxes you will also find overviews of important newsletter tools and newsletter plugins for WordPress. So you have everything you need for the start.

But how do you evaluate the success of your emails? How do you know what is well received and what is not?

What actually is a success in email marketing?

If you offer a newsletter as a freelancer or agency, then this email offer is usually not the actual product. Of course, there are newsletters that refinance themselves through advertising or paid subscriptions. But most likely, at the end of the day, your emails are more of a means to an end. You may want to become better known. You want to attract more customers or generate repeat business. You want to make more sales.

When I present you with possible measurements below, you should always keep this in mind: What is your goal? What do you ultimately hope to get out of email marketing?

Because only when you have your goal clearly in mind can you judge whether you are getting closer to it or not.

Email marketing KPIs and their strengths and weaknesses

Virtually every email marketing service like Sendinblue, Cleverreach and others will give you statistics on your subscriber lists and sends. Unfortunately, these metrics are not always as reliable and meaningful as you might want them to be.

Number of subscribers

A basic value is, for example, the number of people who have signed up to one of your mailing lists (or perhaps even to several, if you offer more than one). Based on this number, you can make a basic assessment of whether interest in your emails is increasing or decreasing. Simply put, if this number is going up, you're probably doing something right. 

However, this number does not tell you how interested the recipients are in your emails. And you can't tell if your email marketing is making a positive difference: are they more likely to take you up on your offer than others? That's an important question that this number doesn't answer.

You might know it yourself: You sign up for a newsletter distribution list because it sounds interesting. But then it ends up in a separate tab in Gmail, which you only look at once in a while, or it gets sorted into a folder by your mail program. It is forgotten.

You will be surprised accordingly: How many "deadbeats" are among your subscribers? 

Despite this limitation, if this number does not increase, you should do some causal research. Here are some questions to ask:

• Is your email concept right? Are the topic, layout, frequency, etc. appropriate for what your target group wants and expects?
• Do you explain your newsletter well enough on the website? Is it clear why people should subscribe? Do you provide all the important information?
• Are you promoting your newsletter sufficiently and in appropriate places?

Bounce rate

When you send your emails, the bounce rate is an important value. It indicates how many messages could not be delivered. A distinction is made between "hard bounces" and "soft bounces":

• Hard bounces are, for example, cases where the receiving address does not exist (anymore). You should delete them from your mailing list as soon as possible. Often your newsletter tool will already do this automatically. Otherwise, receiving mail servers such as Google could get the impression that you are a spammer with many invalid addresses. And you want to avoid that at all costs.
• Soft bounces can happen if a mail server was unavailable for a moment. Your newsletter tool will usually try to deliver these messages again later. Here, too, you will have to sort out recipients that you simply can't reach anymore. This is annoying, but your good reputation as an email sender is more important.

Unsubscribe Rate

The unsubscribe rate in turn shows you how many people unsubscribe from your mailing list. The reasons for this can be manifold. The content itself is not always to blame. Perhaps the interests have changed or a job change is imminent. Nevertheless, it can be useful to keep an eye on whether certain types of messages or certain topics have a higher unsubscribe rate than others.

Spam rate

The spam rate, in turn, is a warning signal, because it shows you how many people from your readership have marked the newsletter as unwanted advertising. Actually, this should not happen at all, because you have legally won your recipients. But people sometimes forget what they signed up for or they can't find the "unsubscribe" link and click on "mark as spam" instead. This is another reason why you should make it as easy as possible for your readers to unsubscribe. 

It's also important that your readers always understand who an email is from and why they are receiving it. For example, I occasionally see that I get a company's newsletter, but it has a person's name as the sender. This can come across as sympathetic or it can be confusing. If your name is your brand, of course it's fine. Otherwise, though, make sure the name that comes up is the one your readership knows and expects.

Opening rate

With the open rate we are now approaching the actually interesting truth. It can show you how many of your recipients have viewed your email. With this value you can theoretically see how active your readers are. You can see how one topic or subject works better than others.

Specifically, the open rate tells you that, for example, 32% of all people contacted viewed the message.

The biggest problem with this measurement is its unreliability. This is because the e-mail protocol itself does not provide for a corresponding function. It is therefore not directly integrated. Instead, newsletter providers and tools work with a simple trick: a transparent, 1×1 pixel graphic serves as a "counting pixel". The system therefore registers as soon as this graphic is retrieved from the server.

Some e-mail programs block such counting attempts for privacy reasons. Or users on the company computer do not see images in e-mails by default unless they activate them - which also deactivates the tracking pixel. Or some people have turned off images on their smartphone so as not to consume so much data on the go.

Therefore, you may have a fan of your newsletter who reads every issue immediately. But in your statistics it looks like this person is completely uninterested in your mailings.

With this limitation in mind, you can still use the open rate for optimization:

• Experiment with subject lines. They should immediately make it clear what the most important topic is and why people should read this email - without slipping towards spam.
• See if you can (better) segment your email lists. For example, existing customers have different interests than people who have never bought anything from you.

Click rate

After the open rate, the click rate is even more exciting. It can show you how many people have clicked on something in your mailings. You can usually evaluate this in a finely granulated way, for example, according to which link was particularly popular.

E-mail automations, for example, use this function to control their processes: depending on whether a certain link is clicked or not, the system then decides dynamically on the next message to be sent.

For companies, the click rate is the most important of the values mentioned so far. After all, this figure shows how many of the people contacted become active.

However, you don't have to evaluate each of your messages strictly according to this criterion. After all, in many cases it is a good idea not to send a purely promotional newsletter, but also to provide useful information that does not always require a click.

But if you use your distribution list to make a special offer, this value is of course very exciting.

This is often implemented technically with a redirect. The links in the e-mails do not lead directly to the target, but take an intermediate step to enable measurement.

However, the significance of this figure is diluted, among other things, by e-mail programs that, for example, call up every link in e-mails in advance in the background and thus click on it automatically. This is primarily for cybersecurity purposes, for example when the system checks at that moment whether a link leads to a phishing website.

Nevertheless, the click-through rate is not useless. If it is low, especially in comparison to the open rate, there may be something wrong with the layout of the email. Maybe your call-to-action is too weak or inappropriate. Maybe you don't explain your offer well enough or the images are inappropriate.

Other ways to measure success

A good addition or even alternative to the click-through rate can be to add measurement parameters to the URLs in your emails. UTM parameters are widely used here. A web analysis tool such as Google Analytics can recognize these and evaluate them separately.

In this way, you can mark website visitors who came in via a newsletter from you. With the appropriate parameters, you can even narrow down which mailing triggered the click. 

In addition, this method allows you to see and understand if, for example, a new order or contact was triggered by a link in one of your newsletters.

However, such URL parameters can be problematic in terms of privacy and data protection. This is one reason why Apple has announced that its mail apps will cut off some parameters in the future. The same applies to the Safari browser in private mode. 

Another way to gauge success is to use special discount codes. If you create them especially for your newsletter readers, you can easily determine how the offer was received based on the usage.

Some notes on data protection

Now I have a damper at the end: I have just mentioned data protection and privacy and the corresponding regulations limit what you are allowed to measure.

In general, you need to inform your users what data you collect about them, how you process it, and why you do all of this. 

When collecting data, you should be clear in advance about how much you actually need it and how detailed it needs to be. For example, collecting a click-through rate for each individual on your newsletter list could be problematic. A general click-through rate that cannot be attributed to individual readers seems much better. Of course, it is interesting to have usage data for every single person in your mailing list. For example, you could target inactive readers with a special mailing. But whether your business interest justifies this is in any case very questionable.

As in the article on the legal issues surrounding email marketing, I must make it clear at this point that I am not a lawyer myself. If in doubt, you should always consult a professional.

Fazit zur success analysis of your e-mail marketing

As with content marketing, you have to get rid of the idea that you can measure success in detail and reliably. Even the well-known values such as the open or click rate are not as reliable and meaningful as hoped.

Nevertheless, you don't have to operate your email marketing solely "on instinct". As shown, the key figures can nevertheless enable statements and indicate trends.

Just make sure you are aware of the limitations of measurability.