This blog entry is work in progress on explaining Playdar. It's not yet clear enough to be turned into an elevator pitch. In particular the third point needs to be broken out into separate points about convenience and quality.
Playdar is special because it is scalable, cheap, and uncoupled.
It is scalable because it is capable of supporting the entire internet.
No single music service can say the same, no matter how big. Every service has its own strengths and weaknesses, with the strengths of one counterbalancing the weaknesses of another.
Spotify is only in Europe, Rhapsody is only in the US. YouTube is the only place for a large pool of amateur content. File sharing networks are the only source for orphaned works that are out of print but still in copyright. Web search is the only way to locate recordings hosted solely by the creators on their own servers. Chinese pop is readily available in businesses that cater to Chinese customers, spanish-language pop is readily available from Latin American companies, and so on for every cultural group on earth, but no business serves all of these customers.
The internet is about federation, not balkanization. Playdar federates. It is a single API for many different sources of content.
It is cheap for web sites because they don't owe royalties.
Webcasting and on-demand streams cost a lot of money. Web providers have a very hard time staying in business. Playing MP3s in iTunes or Winamp doesn't cost anything. These companies have no trouble staying in business. Playdar allows web apps to use the same technique as software on your PC. This saves money.
Web sites can do music cheaply by ignoring the risk of lawsuit and hosting MP3s for themselves, but if they have bad luck it will cost them even more than webcasting or on-demand streams.
Playdar doesn't evade payment and licensing, though! It reuses sources that are already paid for, which enhances their value. Playdar makes it possible for a user who buys an MP3 from Amazon to reuse their purchase on Pandora.
It uncouples MP3 sources from discovery and management.
With Playdar getting MP3s and other music media is distinct from using them, so that you use one tool for getting and another for playing or organizing.
This lets you use the best tool for the job. You should be able to have the best music player and the best source of music even if they aren’t from the same vendor.
It also makes it more convenient to share songs, because people can use the same link even if they have different ways of getting music.