It is the rate that businesses get by dividing the total number of e-mails sent to their target audience by the number of recipients who opened those emails. The open rate is a very important metric for measuring the success of e-mail campaigns.
Open rate shows the number of emails you sent to your recipients have been opened, if this ratio is high, it will ensure your sales rates will increase. Because, the higher your opening rate is, the more people your offers, promotions, information and special campaigns you send reach.