Hi,
These statistics are not accurate and I would not rely on it to delete subsribers.
There are several reasons why these numbers are not accurate. Since we can't look inside someones mailbox we only can see an email is opened in case they clock on a link or when the tracking pixel (1x1 px transparent) is loaded. And the latter is nowadays also not reliable anymore.
Most email clients do not display images as a securty measure by default. So if someone opens your email, reads it, does not clock on a lionk and does not display images the subscriber has read your email, but you don't see it as opened.
Then we have email clients that strip the tracking pixel from the email. Even when they display images, the tracking pixel will not be shown and you email is noit recorded as opend.
The are email servers that thoroughly check your email for spam and virusses. They actually open the email, load the tracking pixel and even follow one or more links in your email. In this case the mail is recorded as opened and clicked on even before the email rarrives in the subscribers inbox.
And there are email services that cache images. Apple for instance does this. These systems are smart enough to recognize tracking pixels and used the cached version regardsless of the tracking information in the link. In this case all opens and clicks are counted towards the subscriber that loaded the images before the system has cached them.
The only reason everyone still looks at the open rate is to check if any changes to your email (change in images, titles, time of sending, etc.) result in a better or worse open rate.
