This is another percentage email metric. But it estimates the number of clicks against the number of opens.
The Click-to-Open Rate measures the performance of the content, design, and message of an email. It also reveals whether an email convinces the recipient to take the desired action.
Click-to-open rate is the opposite of click-through rate – the former is the number of clicks out of the number of opens, rather than the number of emails that get to the recipients’ inboxes. It is a more accurate measure of how the design and message resonated with the target audience, after all, the clicks here are only from recipients that opened and read through the email.