(The following was written by Patrick Knight, Director, Client Deliverability, and myself.)

When you send out an email campaign, you need to know how many of your subscribers actually took the time to click on your message and open it. This measurement is called the “open rate.”

The open rate compares the number of people who opened an email message to the number who did not. It\’s a percentage of the number of messages “delivered.” An open rate is dependent on a number of different factors. It could be affected by aesthetic reasons, or it could reflect your data management, which in turn may have to do with deliverability issues.

For instance, if your email is blocked by Yahoo!, and the majority of your subscribers have Yahoo! email addresses, the open rate for your email campaign may be disproportionately low.

On the aesthetic side, an open rate is influenced by things like the subject line, sender identification, HTML rendering (such as how the email is show on a mobile device), bulk folder delivery, relevancy of content, and timing of send.

Sometimes a message might be reported as having been opened multiple times. This may happen for a number of reasons. For example, email clients such as Outlook render HTLM within the preview pane, so that each time the user scrolls through his or her inbox and passes your message, it will count as an open. This happens because each time the user previews the message, the user is actually requesting the embedded image from your server, resulting in the report of an open. Ultimately, this would be counted as multiple opens versus a unique open.

Unique opens are somewhat like total opens. The important difference is that only one user is being counted or reported. For example:

  • User #1 – opens email 2 times.
  • User #2 – opens email 4 times.
  • User#3 – opens email 4 times.

This makes a total of 10 opens. However, there are 3 unique opens.

Whether or not emails are opened consistently is largely based on sender reputation, relevancy, and other factors mentioned earlier. Although open rates render inconsistencies, email is very much about building a relationship with your subscribers. As you achieve this through relevant content, setting and honoring expectations, creating trust with your brand, and following best practices, email open rates tend to increase.

An increasing email open rate is indicative of a campaign\’s success, even if it\’s not absolute. A number of factors can increase open rates, which are the starting point of determining the true impact of your campaign. Increasing email open rates can depend on a variety of factors. For example, open rates only account for HTML emails, not plain text.

Other things to consider: Is the origin of your list in-house or not? Have you emailed these people before? Are you sure this is the content they want to receive? The more you follow best practices and keep up list hygiene, so too will open rates be more optimal. At mobileStorm, we have experienced professionals who can provide guidance on best practices and offer strategic services to ensure that you stay whitelisted as a sender. With our constant monitoring of deliverability statistics and relationships with ESPs like Google, AOL, and Yahoo!, you have the best chance of getting delivered.

Four of the most important factors a marketer can control in terms of increasing open rates are:

  • To build ongoing relationships.
  • To develop a trusted “from address.”
  • To create relevant subject lines and content.
  • To encourage recipients to add you to their safe senders list.

True, by itself an open rate can\’t serve as a complete gauge of the impact of the campaign. It is only a starting point, because an “opened email” doesn\’t necessarily equate to a “read email.” Moreover, it doesn\’t tell you whether or not the recipient completed the marketer\’s desired action. Other metrics such as the render rate can help create a more complete picture, with data such as click-through information, delivery failures, conversion data, etc. Having said all that, however, it\’s important to know that along with other metrics, the open rate gives you a starting point to determine how your campaign performed.

(The preceding was originally a two-part series that appeared in mobileStorm’s email newsletter about digital marketing, Outside The Inbox. Such articles offer in-depth instruction to messaging marketers, new and experienced alike. To make sure you don’t miss any of this valuable advice, subscribe to Outside The Inbox today!)