If you are 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 look out for.

Previous parts of this article series have already covered the right concept, how to gain more readers and legal issues. In two further articles here at Raidboxes, you will also find overviews of important newsletter tools and newsletter plugins for WordPress. So you have everything you need to get started.

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

What actually constitutes success in email marketing?

If you offer a newsletter as a freelancer or agency, for example, then this email offer is usually not the actual product. Of course, there are newsletters that are refinanced through advertising or paid subscriptions. But at the end of the day, your emails are most likely a means to an end. You might want to become better known. You want to gain more customers or trigger follow-up business. You want to generate more sales.

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

Because only if 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 such as Sendinblue, Cleverreach and others will give you statistics on your subscriber lists and sendouts. Unfortunately, these metrics are not always as reliable and meaningful as you would like them to be.

Number of subscribers

A basic value is the number of people who have subscribed to one of your mailing lists (or perhaps even several, if you offer several). Based on this number, you can make a basic assessment of whether interest in your emails is increasing or decreasing. To put it simply: if this value is going up, you are probably doing something right. 

However, this number does not tell you how interested the recipients are in your emails. Nor can you assess whether your email marketing is bringing about a positive change: are these people more likely to take up an offer from you than others? This is an important question that this figure does not answer.

You may be familiar with this yourself: You subscribe to a newsletter mailing 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 is sorted into a folder by your mail program. It falls into oblivion.

You'll be surprised: How many "dead bodies" are among your subscribers? 

Despite this restriction, if this figure does not increase, you should investigate the cause. Here are some questions to ask:

• Is your e-mail concept right? Are the topic, layout, frequency, etc. suitable for what your target group wants and expects?
• Do you explain your newsletter well enough on the website? Is it clear why people should sign up? Do you provide all the important information?
• Are you advertising your newsletter sufficiently and in the right 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 in which the receiving address does not (or no longer) exist. You should delete these from your mailing list as soon as possible. Your newsletter tool will often do this automatically. Otherwise, receiving mail servers such as Google could get the impression that you are a spam sender with many invalid addresses. And you want to avoid that at all costs.
• Soft bounces, on the other hand, can happen if, for example, a mail server was unavailable for a moment. Your newsletter tool will usually try to deliver these messages again later. Here too, however, you will have to sort out recipients that you simply can no longer reach. 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. There can be many reasons for this. The content itself is not always to blame. Perhaps their interests have changed or they are about to change jobs. 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, on the other hand, is a warning signal, as it shows you how many people from your readership have marked the newsletter as unwanted advertising. Actually, this shouldn't happen at all, as you have legally won over 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 is 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 receive a newsletter from a company, but it has a person's name as the sender. This can be appealing or confusing. If your name is your brand, it's fine of course. Otherwise, however, make sure that the name that your readership knows and expects appears.

Opening rate

With the open rate, we are now approaching the really 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 to what extent one topic or subject works better than others.

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

The biggest problem with this measured value is its unreliability. This is because the e-mail protocol itself does not provide 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 "tracking pixel". The system registers as soon as this graphic is retrieved from the server.

Some email programs block such counting attempts for data protection reasons. Or users on company computers do not see any images in emails by default unless they activate them - which also deactivates the tracking pixel. Or some people have switched off images on their smartphone so as not to consume so much data while on the move.

It can therefore happen that you have a fan of your newsletter who reads every issue immediately. But in your statistics, it looks as if this person is completely uninterested in your mailings.

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

• Experiment with the subject lines. They should make it immediately clear what the most important topic is and why people should read this email - without slipping into 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 fine granularity, for example according to which link was particularly popular.

E-mail automation systems, 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 do not 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 mailing 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 emails do not lead directly to the destination, but take an intermediate step to enable measurement.

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

Nevertheless, the click rate is not useless. If it is low, especially in comparison to the open rate, there may be something wrong with the design of the email. Your call-to-action may be too weak or inappropriate. Perhaps you are not explaining your offer well enough or the imagery is inappropriate.

Further options for measuring success

A good addition or even alternative to the click rate can be to add measurement parameters to the URLs in your emails. UTM parameters, for example, are widely used here. They can be recognized by a web analysis tool such as Google Analytics and evaluated separately.

In this way, you can identify website visitors who came to your website via a newsletter. With correspondingly extensive parameters, you can even narrow down which mailing triggered the click. 

You can also use this method to see and understand whether, 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 of the reasons why Apple has announced that the manufacturer's mail apps will cut off some parameters in future. The same applies to the Safari browser in private mode. 

Another way of gauging success is to use special discount codes. If you create these specifically for your newsletter readership, you can easily determine how the offer has been received based on usage.

Some notes on data protection

There's one more damper at the end: I've already mentioned data protection and privacy and the corresponding regulations limit what you can measure.

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

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

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 specialist.

Fazit zo analyze the success of your e-mail marketing

As with content marketing, you have to say goodbye to the idea that you can measure success in detail and reliably when it comes to email marketing. Even the well-known values such as the open or click rate are not as reliable and meaningful as hoped when you take a closer look.

Nevertheless, you don't have to run your email marketing based on "gut instinct" alone. As shown, the key figures can still provide information and indicate trends.

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