The spectrum of metrics in email marketing is enormous, starting with numerous performance KPIs which exactly reflect the online behavior of each customer, all the way to real-time data from a variety of social networks. Thus, it is no surprise that many feel overwhelmed by this flood of data.

Although advanced analysis tools for sure support any decision making process, you should know the following metrics at all costs, regardless of the analysis solution used, for today’s successful email marketing:

1. The Inbox Placement Rate (IPR) indicates how many of your emails end up in the inbox of the recipient and not in the spam or junk folder, or get even completely lost. Don’t get confused with the IPR, which is the number of emails sent minus the returns (bounces), because in the contrary, the incoming email rate provides an indication of delivery problems. Nowadays, around 20% of solicited, opt-in, marketing emails are not reaching the recipient and if the email does not reach the inbox, it can’t be opened and consequently neither generate a click nor achieve ROI.

2. The Complaint Rate is the percentage of your emails that was delivered to the inbox, only then to be marked by the subscriber in his mail program as junk or spam. This figure is mainly important because it indicates how many of your opt-in users are dissatisfied with your emails. There could be many reasons for that, such as for instance that your recipients may have disapproved the contents of the email, or didn’t like the frequency of the email messages, or the application process was simply too confusing and no email has been expected. Complaints are one of the most important criteria that determine your sender reputation. And when you envision that 77 percent of the filter decisions of ISPs are based on the sender's reputation, you should never lose sight of this operating figure.

3. The Unknown User Rate indicates the percentage of email addresses that do not exist anymore. ISPs in general punish high unknown user rates, as they are seen as a sign of poor list hygiene. The ISP has to assume that the sender uses old or purchased lists, similar to what usually spammers do.

4. Spam trap Hits are an essential feature of a missing list management, indicating the number of real or recycled spam traps. Spam traps reach your mailing lists, for example, when you buy lists from not absolutely reliable sources, or if you are using outdated data. Email addresses that have never or are no longer active are converted to spam traps, impacting extremely negative your sender reputation.

5. Opening rate according to end devices: With the growing popularity of mobile devices and their use for reading emails, at the same time increases the relevance of data usage of these devices in your target market. Only in this way the success of your email program can be ensured in the long term. Emails that are not optimized for mobile device will, for instance, often be closed immediately or simply get deleted.

6. Reading Rate: This relatively new index should ideally be interpreted in combination with the commonly used open rate and click-through rate, because they have a different perspective on the commitment of the subscribers – such as how they interact with your emails. The reading rate differs from the opening rate, as openings are not pixel-based measures, but are rather based on the information from the email provider, such as e.g. Yahoo! or Google.

Nowadays, intelligent and successful email marketing is more important than ever. By measuring, interpreting and optimizing key indicators consistently, you can ensure that your emails will be received, opened and read.

By Daniela La Marca