I'm planning a Salesforce & MC implementation and the client would like to include GDPR compliance.
We will be building a custom subscription centre (possibly using Formstack as I think I prefer it over Cloud Pages). Salesforce will be the Database of Record / Single Source of Truth. The Salesforce Record ID will be used as the MC Subscriber Key.
I am considering using the Salesforce Individual object, which has very little actual functionality currently. However it could be used as the store of Subscriber preferences. Using the Individual Record ID as the Subscriber Key in MC would also avoid the issue that Marketing Cloud Connect doesn't handle Lead Conversion - the Individual record doesn't change during this process.
That said, using the Individual object as the link to the Lead or Contact means you either need to have a formula field on the Individual object looking up to the Lead or Contact for the fields your require read access to for MC, or you have to span another layer when referencing something in MC (i.e. Individual>Lead/Contact>Field ). This is likely to cause some issues.
Interested to hear everyone's thoughts!