Music subscription services are still yet to prove themselves in the market, but I really think they are the future of music online. Rdio is a very new player to this market, but they have already been making quite a huge stir. Rdio was co-founded by serial entrepreneurs Niklas Zennstrom and Janus Friis, who previously started Skype, Kazaa and Joost.

Rdio is set to launch into an invitation only beta later this week, but only in the USA. Rdio is a streaming based cloud music service by which users will be able to access a library of millions of songs for a flat monthly fee. Desktop and mobile access via iPhones and BlackBerrys costs $10 monthly, while desktop-only customers pay $5.

There are already a lot of players in this space, such as MOG (in the USA) and Spotify (in Europe), Thumbplay (USA) and Rhapsody (USA). A lot of people are betting that this will be the type of music service that will win out in the end, but I think there are already to many players in this market and I think it is going to be a winners market (only a couple will survive).

Disclosure: Spotify, Thumbplay and MOG are all RouteNote partners. We hope Rdio will also be a partner very soon!