Audience research
What the data cannot answer comes back as a question.
Suppression, consent state and exclusion lists get applied before delivery, not as a correction afterwards. A record you asked to be withheld stays withheld.
Change tracking
What moved since the last delivery, so a refresh does not read as a new universe.
Segment design
Deciding the cuts with you, against what the data can actually support.
Gap reporting
What is missing from a universe, named rather than rounded away.