Our Marketo instance is integrated with Salesforce, which provides a small percentage of leads to our lead database. A majority of our leads are imports to Marketo from a database NOT integrated (not supported at this time). Because of this, Salesforce is creating many duplicates to the Marketo database that already exist from the other system's import.
Any thoughts on how to get Salesforce to auto-associate a new SFID with an existing record in Marketo before trying to sync a new record over to Marketo?
On top of Josh point,
1/ You should always run external system import after all data has flown from SFDC to Marketo, meaning, after any import made to SFDC as well.
2/ It is also recommended that you push all new Marketo lead to SFDC, assigning them to queues if necessary, so that all of them are "known" to SFDC when you run duplicate prevention tools in Salesforce. This will make sure that duplicates are not created in SFDC in the first place.
-Greg