My Marketo Campaign 'list' came from a report of specific 'Business' LEADS in Salesforce. When returning the LEADS to Salesforce, ~600 new 'Person' LEADS were created in spite of the fact that all of the LEADS came from Salesforce in the first place. Sorry if the terminology is not correct, I am very new to this Marketo/Salesforce process.
Hi Laurie,
It is likely you have a "sync with Marketo" flow step in a smart campaign with a assignment to a Queue. If you do this on a SFDC contact, this will recreate a lead in SFDC (and a duplicate in Marketo).
-Greg