Why can't Meta predefine the Engaged Audience and Existing Customers audience segments for us? They have the data to do this. Advertisers can't utilize Audience Segments -- and see the power they provide -- until these segments are defined. Many advertisers are confused, or completely oblivious, about how to define them -- and why they should. By predefining these audience segments, it eliminates a step. Advertisers should still be able to edit and augment the lists, but this could be a helpful start.