For email marketing campaigns, many users may not always open the emails you send to them. Much like click through rate, the open rate is an important metric when measuring the success of email campaigns.
In this instance this means the amount of subscribers who have opened their email once it has been delivered to their inbox. Depending on your audience this will be a metric that we will measure when it comes to email marketing. Understanding how emails are being opened by your subscribers list helps us grow brand loyalty and sales over time.