When dealing with duplicate leads, Marketo should stay consistent on which lead record is considered the active/current lead
If you have duplicate lead records in Marketo, it's important to know which record Marketo considers the "active" record. Consider the following example:
Sending Batch Emails
If there are duplicates within your email list, only one email will go out. It will be the lowest Marketo ID (created first). This record is also used to populate tokens. Example:
Created | Updated | Marketo ID | First name | |
3/13/2010 | 4/13/2010 | 2749 | Elizabeth | beth@company.com |
12/15/2012 | 3/15/2016 | 10936 | Beth | beth@company.com |
In this case, the email will be sent to the first record with Marketo ID 2749. It will say “Dear Elizabeth” if you use a token for first name. Also, the activity entries will be attached to that record (sent, delivered, opened, clicked). When the email click goes to a page with Munchkin code in it, any web visits will also be associated with this record.
[EDIT 1/30/2018]: apparently this is not the case. As you can see below in the latest comments, @Aaron Dear uncovered a serious issue/bug - especially if you have a lot duplicates in your instance (in some cases, these duplicates are intentional). Basically, there is no defined logic to determine which lead record is used when evaluating duplicates as part of a batch email campaign.
List Uploads
When a lead is included in a list import and the lead already exists in Marketo, it will affect the most recently updated record in Marketo (updated last) - in this case, the record with the first name "Beth". If you're intention was to ensure Beth's record had the most up-to-date information so that some of that info could be used in an email send, you're out of luck. Marketo will use "Elizabeth's" record for that send.
We’ve been running into issues with duplicate leads that exist in the same lead partition – specifically when sending batch emails that include tokens for Sales Execs (BDE) First, Last, and Email. To ensure this info is updated before an email goes out, the marketer will make sure the list import contains the most recent data. The emails still went out with outdated content/data. Uploading a list with updated data won’t matter (when there's a duplicate) since Marketo doesn’t use the most recently updated record in Marketo when sending out the email.
Obviously, the main objective should be to deal with duplicates appropriately and regularly. But this often is easier said than done.
When duplicates exist, I would like to see Marketo treat the active record consistently - in this case, the same for when sending batch emails AND list uploads - so that we can be certain our emails contain accurate personalization data.
To see Marketo's full list of duplicate rules, head over to the discussion: If duplicate leads are an issue, be aware of how Marketo determines which lead is active