Salesforce to Marketo sync causes duplicate lead

[Anonymous]

Hi all,

I've encountered a strange behavior while wiping my "activities" in salesforce and re-importing everything to start on a clean slate, when it comes to Salesforce synching with Marketo.

What happens is that once all activities are deleted in salesforce, their corresponding lead in marketo records a "Delete Lead from SFDC" in the lead's activity log. But once the lead is re-imported (in salesforce), a new and duplicate lead is created in marketo with the same name/email...etc.

This obviously is not optimal because we'll lose all data we have on the lead (including source that brought the lead in, landing page they landed on first on the platform...etc).

I need to know what's the best approach as we need to clean everything on salesforce and do a mass import as we're moving from another system to sales force and our marketo instance has been running for 5+ months now and has been accrueing data on our leads.

Thanks in advance.

[Anonymous]

By "activities" are you referring to deletig the SFDC Lead records themselves or just their Activities / Tasks?  If you deleted the Lead records, that would cause the "Delete Lead from SFDC" activity to each lead's Activity Log and would change the SFDC is Deleted field from false to true as well.

If you are "importing" the records back into salesforce from a CSV file, that is likely what is causing the duplicate.  If you were to delete all of the Salesforce Leads and then use the Synch Lead to SFDC flow action on all of the Marketo lead records in Marketo, just a single new Lead record should be created. 

Be aware that if you also have Contact records in Salesforce and delete them, and then synch their Marketo lead records back to Salesforce, only new Leads will be created. not Contact records.