Pandora is positioning the messaging service as a continuation of an initiative to give more tools to music artists, as Pandora competes with newer music services such as Spotify for both listeners and artist support. In October, for example, Pandora unveiled a new, free analytics service for artists that gives them information about where their listeners on Pandora are from, and which songs they are favoriting the most.
via Pandora Launches Message Service for Music Stars to Connect With Fans | Re/code.