How does Segmentation work in Data Cloud and what is waterfall segmentation?

Segmentation in Data Cloud uses a drag-and-drop Segment Criteria Builder to define audience rules against Unified Individuals and related DMOs. Key concepts:

1. Segment-on-Segment — build a segment using another segment as an inclusion or exclusion criteria, enabling hierarchical audience logic.
2. Waterfall Segmentation — a controlled segment strategy where individuals flow through priority-ordered buckets and are assigned to the first matching segment, preventing overlap across buckets (e.g., "Platinum → Gold → Silver → Standard").
3. Refresh Schedule — segments can refresh every 12 hours (Rapid Publish) or every 24 hours (standard). Rapid Publish requires an Activation to also support near-real-time processing.
4. Segment Membership Table — a DMO that records which Unified Individuals belong to each segment at each refresh, providing historical membership data.