Will salesforce use custom fields for syncing?

[Anonymous]

We have a need to have a numerical field that is unique to individual people, but is not an email address (the current unique identifier). This unique numerical field will match the same one in salesforce. Is it possible to sync the salesforce record (so the information that get's put into salesforce from a rep, such as first name, last name, company, title etc) into Marketo without an email, and just this unique identifier? If not, what are the suggested work arounds?
 

[Anonymous]

I'm not sure I 100% understand, but if email is not a required field to create a lead record in your SFDC instance, I don't see why you couldn't do this.  Once you create a lead record in SFDC Marketo will just sync it over with whatever information is available on the CRM side..

[Anonymous]

also: all records already do have a numerical unique identifier (SFDC ID, and Marketo also appends its own ID field) -- can you use that in this case, or do you have to generate an additional id for something else?

[Anonymous]

I'm concerned wih it creating duplicate records. And unfortunately we need more than th SFDC ID/Marketo ID because it's an ID to work with our software to monitor behaviours.