What will happen after I exhaust the 3000 visitors in my free account?
Once you reach a subscriber number of 3000, you won't be able to send notifications to
your new subscribers. The opt-in, though, would still be active on your
website and you can keep collecting more subscribers. After hitting the 3000 limit,
you'll have to upgrade to one of the paid plans to be able to send notifications to the
new subscribers you have collected.