We are trying to build a relationship between Marketo and Salesforce where the only records that come into Marketo (apart from inbound leads) are Salesforce records associated with synced campaigns. This means traditional sharing rules won't really work for us. If we built a checkbox to identify which records to sync, how would we know when to un-check it?
For example, if a Salesforce Lead is added to a Salesforce Campaign synced with Marketo, it could check the box, giving Marketo visibility, and creating the record in Marketo. When the campaign completes, Marketo can uncheck the box, delete the record from Marketo, and the record stays in Salesforce and stays associated with the Salesforce Campaign. Simple enough.
However, if a lead is added to 5 marketo campaigns, has completed 3 of them, but is still active in two synced campaigns, how can we build logic to tell Marketo to keep that lead if and only if it is a part of a synced campaign?