Now you can create broadcast lists based on groups and user properties, and the exact recipients will be determined when a broadcast is sent. If you add a group or a user property to a broadcast list, then the broadcast will be sent to everyone who is a member of that group, or has that user property value, at the time the broadcast is sent. You also can even add other broadcast lists to a broadcast list.
You can add any number of groups, properties, or other broadcast lists to a broadcast list. And you can add any combination of groups, user properties, lists and individual users.