What action can a user take if a segment shows an estimated audience size of zero?

When a segment shows an estimated audience size of zero, it indicates that the current criteria for that segment do not match any data within the dataset at the moment of evaluation. Choosing to wait for the next scheduled evaluation can be a valid action because the data in Adobe Experience Platform is dynamic and may change over time. This means that new data could arrive or existing data could change, potentially resulting in a non-zero audience size in future evaluations.

Waiting allows the system to account for any updates or additions to the relevant datasets that could make the segment applicable to new users or items, and thus yield a different audience size. It is important for users to understand that segments are often evaluated on a regular basis, and using this time allows the system to catch up with any data ingestions or updates.

While the other options like disabling the dataset or changing the primary identifier might seem like potential solutions, they do not directly address the issue of segment evaluation and might result in unintended consequences or further complications. Hence, simply waiting for the next scheduled evaluation is a reasonable and straightforward approach to see if the audience size changes.