I’ve just gone through this process of deleting lists and will add what I learned… Please note that I’m an AC customer and not an employee. Also, always backup your contacts before making material changes.
When you delete a list, there are two possible outcomes for each contact on that list. First, if the contact is subscribed to one or more other lists, the contact will remain a contact in your account and the list you are deleting will be detached from their contact record.
Second, if the contact is only subscribed to one list and it’s the list that you are deleting, then this contact will be completely removed from the contact database in your account.
Now, for those contacts who are only on the list you are about to delete you can do a couple things. Before you delete the list you can perform an edit that removes them from the list (though I tend to think of removing the list from the contact). The challenge with this is that they and any others that you manually remove or “unsubscribe” from the list will be marked in AC as having been “unsubscribed” and it might lead you to think that they actually unsubscribed from a campaign email. When you go this route, you will end up with a group of contacts who are presently NOT subscribed to any list at all.
What I did, since I was actually consolidating lists, was that I identified those contacts who were on the list to be deleted and not on any other list and then I added them to another list in bulk edit before I then deleted the other list. What this step did was to make sure that everyone on the list to be deleted were also on another list such that I didn’t have to unsubscribe them prior to list deletion and their contacts records weren’t deleted because I had just added them to another list.
I hope that isn’t too confusing. It’s certainly less confusion that the message you get from AC as you are deleting a list which says that all contacts on that list will be deleted. This message isn’t accurate. It needs to be changed to say that only those contacts who are subscribed to only that list and no other list will be deleted. They could also add something to say that any contacts on one or more other lists will not be deleted.