If the email address is the unique identifier, then how are duplicate email addresses made?
In our database, we have some people whose entire information including email are the same. The only thing that differs is "Updated" and "Id." The only ways for this information (in our case) to be imported are through lists, and form fills. And I read on a thread in this community that Marketo only dedupes when the email is entered directly into it from Lists, API, or Form Fills. So just wondering why/how this is happening?
Is your instance integrated with your CRM? If so, and someone enters a new lead/contact in CRM (and syncs to Marketo), Marketo creates a new record on the Marketo side rather than dedupe against an existing record.
This happens alot and there are lots of culprits. If you have an API adding and creating names and they don't check for whether the lead exists or not it will create a duplicate but most likely your culprit is your CRM.
I know it's been a while, your information was very helpful, and we thought we had it figured out ...
However, what if we are manually uploading our leads with .csv lists, and thus overriding the information with each load? Any thoughts on how duplicate emails could be created then?
Mariah - when importing a list directly into Marketo, Marketo will dedupe against any existing records where email address is the same (and no duplicates will be created). There is no way to "override" this. Now if you're referring to updating those records with new/updated data - then yes, the existing records will receive those updates as long as you're not block field updates as part of a list import.