4 of 4 people found this helpful
The initial sync will push everything in SFDC into Marketo. But by default, it will not push everything in Marketo to SFDC.
As you point out, Marketo does not deduplicate what comes from SFDC, so the result is that it may indeed create duplicates in Marketo if the same people are already there, from your previous campaigns or manual imports.
So the first thing you may want to do in Marketo after the initial sync is to cleanse these duplicates and merge the non sync'ed leads with the leads /contacts coming from SFDC. You might want to consider services such a Marketo's Easy Merge of Marketo Apps | Leadonance (contact Paul Trushin).
Then, if a lead in SFDC is converted, Marketo will automatically map with the existing contact and from there will continue sync'ing with the contact.
Thanks this was really helpful!