Hi Tony,
Thanks for your question! The Target API does not support Activity-only Audiences. As I'm sure you have some follow up questions and would like to learn more about Audiences, I highly recommend joining us this Thursday, January 25th at 10am PST for the Discovering and Managing Audiences for Maturity webinar (part of the Personalization Thursdays webinar series).
Check out the event description below, and register here for further event details!
The quality of audiences and segmentation are a key ingredient in the effectiveness and the maturity of any optimization and personalization program. In this webinar, we'll learn how to discover what are important profile attributes for audience segmentation, where to build and govern our audiences and audience personalization best practices.