Munchkin/associateLead - if two Leads have the same email, what does it use?

[Anonymous]

• Multiple Marketo leads can use the same email address.
• Munchkin::assocationLead uses the email address to sync cookie and lead

So given the above, when multiple leads share an email address, which lead gets assigned?

The docs are unclear on this point:
http://developers.marketo.com/documentation/websites/lead-tracking-munchkin-js

[Kenny_Elkington]

Hi Grant,

If the cookie value being submitted already matches one which is associated to an existing record, then it will update that record.  If the cookie value is not associated with either, the most recently updated record is the one which will be updated.

[Anonymous]

That's not very cool.

Can associateLead use any other attributes to disambiguate the target lead?  Could I pass it the Marketo ID?  Or the foreignPersonSysID?