I have a question regarding a data migration that one of our clients want to do. So they currently use lists in marketing cloud where email is the unique identifier. They have planned to export data from marketing cloud and import it into salesforce in order to generate a contact ID for these subscribers and use them with the current Salesforce setup. All of this data will then be imported in marketing cloud with Contact ID as the Subscriber Key.
Their question is related to what they should do with the data currently residing in marketing cloud?
- should they export the unsubscribes as well or leave the unsubs with the email address as subscriber key in marketing cloud?
- should they delete or keep this data in marketing cloud?
Obviously for tracking purposes they need to do a data matching in order to preserve the current tracking data in marketing cloud.
Any guidance on this is appreciated.