Many privacy regulations require deletion of identifiable customer information when appropriate.
At the same time, organizations often retain anonymous or aggregated performance metrics that no longer identify individuals. Separating reporting from personal data supports compliance while preserving valuable business insights.

For a simple segmentation strategy, using a List model combined with Groups (filtered or random) is the easiest approach. Lists are simpler than Data Extensions, require less setup, and Groups allow basic segmentation directly in Email Studio or Journey Builder for Single Send Journeys.

A Salesforce Report is the correct recommendation because it is the tool Sales Cloud users themselves can build and manage manually, directly within their familiar Salesforce interface, without needing any Marketing Cloud access or technical skill - critically, Salesforce Reports natively support combining both Lead and Contact records (through report types built for that combination), and once built, such a report can be directly selected as the target audience within Email Studio ' s Send Flow via Marketing Cloud Connect, which specifically supports sending to Salesforce Reports as an audience source. This directly satisfies the requirement that Sales Cloud users - not Marketing Cloud specialists - are the ones manually creating the segment. Automation Studio (A) and Salesforce Data Extensions or Synchronized Data Extensions (D, B) all require Marketing Cloud-side configuration, SQL knowledge, or Contact Builder access to build and maintain
- none of which are accessible or manageable directly by Sales Cloud users working purely within their own CRM interface, working against the explicit ' Sales Cloud users to manually create ' requirement. The Salesforce Report send-flow integration is specifically designed for exactly this kind of CRM-user-driven, cross-object (Lead and Contact) audience creation. Reference: Marketing Cloud Connect Send Flow, Salesforce Report Audiences.