Marketo Certified Expert Certification Practice Test 2026 - Free Marketo Practice Questions and Study Guide

The "Possible Duplicates" smart list in Marketo is designed to identify potential duplicate leads based on certain key attributes. By default, it uses the email address as the primary identifier because an email address is unique to each individual and is generally the most reliable method for distinguishing between different records. This helps ensure that the system can accurately assess whether two records might represent the same person, considering that multiple records for the same individual could exist in the database.

Other attributes, such as last name or full name, could lead to false positives since they are not unique identifiers. Two individuals can have the same last name or even full name, which doesn't guarantee they are the same person. Using unique attributes like email addresses minimizes that risk and improves the accuracy of duplicate detection in the system.