Stop Mailchimp unsubscribes. Let subscribers choose preferences

I often get asked how, instead of unsubscribing, it’s possible in Mailchimp to ask contacts to choose which email categories they’d like to receive. Unfortunately there isn’t any obvious means of doing this in Mailchimp; as a person clicks ‘unsubscribe’ they are immediately marked as unsubscribed in Mailchimp and you’re unable to send further email marketing to them.

It is however possible to request subscribers to select their preferences using Mailchimp Groups and this instructional video shows how to do this.