Replace Plex playlist tracks automatically on a Last.fm playlist
Plex media server allows you to aggregate all your personal media and access it anywhere you go.
Using a music recommender system called Audioscrobbler, Last.fm builds a detailed profile of each user's musical taste by recording details of the tracks the user listens to.
Soundiiz is the most complete online tool to manage your music library between multiple services. It offers a simple way to import and export playlists and favorites tracks, artists, and albums.