It’s always interesting to see how many people still open and read email campaigns long after they’ve been sent. Look at the screenshot below…
This is a report for an actual campaign someone sent from MailChimp. It was sent in May, and people are still opening in August. They clicked a full month after it was sent!
So what? Well, if you’re keeping copies of all your email newsletters on your website (such as in an "archives" section) you might want to make sure you don’t overwrite previous editions too soon. Consider just archiving each issue into new subfolders, named by date or something.
If you’re using MailChimp’s AIM Reports to send followup campaigns to all your recipients who didn’t open your first campaign, give it some time. Don’t send your followup too soon, because the majority of your recipients will take a few days before they get around to opening your emails.