From the Rdio blog:
Today, we’re thrilled to announce that we are growing our team with the acquisition of TastemakerX, a leading music discovery and curation service. Based in San Francisco, TastemakerX was founded in 2011 to help artists connect with fans. TastemakerX enables listeners to discover new music, build and listen to virtual collections, and view artists based on social discovery.
The interesting part, as noted by Brad Hill at RAIN News, is that this acquisition follows the news of Spotify acquiring The Echo Nest (the leading music intelligence company) back in March, when I purposefully included a note on third-party services using it for essential music discovery/recommendation features.