Working With Duplicate Leads in Marketo

June 20, 2013 Laura Kirkland

Marketing automation is much more effective when populated with accurate lead information.  Marketo and (SFDC) offer easy-to-use solutions that manage and merge leads in order to maintain a quality database.

Most Marketo customers have many duplicates that originate or develop from direct entries or list uploads.  The duplicates result from the existence of multiple, valid email addresses per person, or from a combination of these and other methods.

It is important to remember Marketo does not automatically de-duplicate pre-existing leads within the database. Therefore, an established merging process can help keep a clean database. It is also helpful to make Marketo the only entry point for all new lead uploads.

Marketo Duplicates

In Marketo, email addresses are the unique identifier for every lead in the database.   When a lead enters Marketo from a form fill, SOAP/Munchkin API call or list import, Marketo will automatically search for a lead with the same email address and update it rather than creating a new lead.

Although Marketo does have functions in place that manage lead duplication, it is important to have a regular data maintenance schedule ensure.

This includes:

  • Regularly querying for leads with matching email addresses and updating to eliminate duplicates.
  • Updates of lead information from the lead record with the most recent activity (except for Lead Source)

Duplicates from SFDC

SFDC gives each new record in the system a unique ID number, a field that is independent of any other and acts as the unique identifier for leads in the system.  This unique identifier allows duplicate email address entries in SFDC.  When SFDC synchs with Marketo, duplicates will be created on the Marketo side. However, if leads are merged in SFDC, Marketo will merge the matching leads in its system as well. Marketo establishes a “master” lead record and send that information back to SFDC.

Marketo qualification rules for establishing these “master” records include:

  • Lead vs. Contact – Contact overrides
  • Lead vs. Lead – First Lead chosen before merging
  • Contact vs. Contact – First Contact chosen before merging
  • Lead vs. Contact vs. Contact – First Contact selected before merging

REMEMBER:  Contacts will always be the primary selection when competing with Lead.  Status and selection order will be the determinant of the Master Record status.


When leads are merged, their entire history is combined with the selection of the fields to be kept in the “master record” determined by the administrator.

There are multiple ways to clean up databases through merging techniques.  Three of the most common include:

A)  One-off merges are done by using the standard “merge lead” functionality in Marketo.

Use case:  When there are a small number of leads to merge in order to maintain clean database.

1)    Navigate to the Lead Database tab.

2)    Select Possible Duplicates under the System Smart Lists.

3)    Sort emails by ascending to group duplicates together.
4)    Select duplicate leads by holding down CTRL while clicking on two different leads.  (It is recommended to merge only two leads at a time.)

5)    Click the merge leads button in the toolbar.

6)    A dialog box will appear with the fields that need merge clarification.  You must decide which field entries you want to keep for that lead (MKTO chooses the most recent activity by default).  No information or tracking will be lost.

**Note:  The Smart List tab contains a “Possible Duplicates” filter for the “Email Address” field.      You can add additional fields (using the green plus in the same filter) to maintain a clean data base such as Full Name.

7)    Click merge – now the chosen information is appended to the lead record and the rest of the information is discarded.

B) DemandTools:  A purchase of a suite of DemandTools for the year enables use over time, and is not limited to the de-duplicating function.

Use case:  When there are large numbers of leads and flexible control is required regarding what information is merged to provide the most accurate records.

IMPORTANT:  When utilizing this feature, select the standard SFDC merge function.  Failure to do this could result in the loss of the history of lead activities associated with multiple leads.

For more information, explore the list of apps available for data cleansing within SFDC.

C)  Easy Merge is an add-on service from Marketo that allows for a one-time, large scale cleanup.  Marketo will work with your team to define which criteria to preserve when merging leads.  The support team at Marketo will run practice rounds to ensure you are happy with the results.

Use Case: When there are large number of leads and personalized criteria for “master” fields is desired.

Regardless of the merge tool selected, it is important to understand SFDC rules.  If, in the process of the merge, a rule is in place that causes the result of the merge to be invalid and SFDC rejects it, that issue will need to be resolved.

About the Author

Laura Kirkland

As Elixiter's Marketing Manager, Laura focuses her creative talents on making sure the team's marketing programs flourish and grow. She enjoys solving the big strategic types of challenges and finds satisfaction in creating innovative solutions that didn't previously exist. She loves being outdoors and exploring the beauty Montana offers whether it’s in a boat on a river or hiking a new trail. Laura is always learning something new - currently she is focusing on long distance running and refining her swing dancing skills.

Follow on Twitter More Content by Laura Kirkland
Previous Article
Marketo Landing Page Robot Definitions
Marketo Landing Page Robot Definitions

No More Articles