Spotify just bought "music intelligence" company, The Echo Nest. In other words, it just bought the data machine that powers rival services like Rdio, iHeartRadio, and others.
The Echo Nest is a "music intelligence" company that uses a combination of machine listening and intense web scraping to build up the databases that power features like personalised radio. Many companies use their own data and proprietary systems, but a lot of them are pretty reliant on The Echo Nest.
So if you use a Spotify competitor "Powered By The Echo Nest" what can you expect? According to Spotify's Graham James:
The Echo Nest does work with direct competitors. We will work with their team to understand these relationships and determine the next business steps. The bottom line is that The Echo Nest will meet all contractual obligations to all customers.
In other words, it's not totally clear what will happen after The Echo Nest's contracts with companies like Rdio are up—whether Spotify will pursue licensing or just pull the rug out.