Last.FM has introduced a free full-track music streaming service, designed to help music lovers identify new sounds they like.

Last.FM boasts 20 million users worldwide. The launch of the new service is a unique proposition because no other service - including Napster - has ever legitimately offered such an extensive catalogue of music for free playback. The added benefit is that users can select what track (or tracks) they want to listen to.

The company has reached deals with all four majors and thousands of indie labels in order to launch its service. Last.FM's move prompted one music industry insider to say: "I bet Napster just wants to go home."

The free-on-demand service will be advertiser supported, and after playing a song more than three times, listeners will be given the option to download the track through iTunes, Amazon and 7 Digital.

Martin Stiksel, Last.FM co-founder, said: "We're giving the listener free access to what is basically the best jukebox in the world. The ability to dip into such a uniquely broad catalogue from your laptop, home or office computer, and listen to whatever you want for free represents a new way of consuming music that in turn might change the way you listen to music. In that respect, nobody else can currently offer what Last.FM is offering right now."

Great content

Last.FM was acquired by CBS in May 2007. President and CEO of CBS, Leslie Moonves, said: "It is clear to us that communities built around great content are increasingly driving traffic and revenue online. We acquired Last.FM because music is one of the best ways to build communities on the internet. Adding such a tremendous collection of content to Last.FM will help it grow by leaps and bounds."

The service also includes an element for unsigned acts. Last.FM's 'Artist Royalty' arrangement means such acts who choose to upload their music to the service will be paid directly from Last.FM, every time one of their tracks is played. This means artists without traditional recording or publishing deals will be able to reach millions of music fans and offer their music for free, while generating revenue.

"We're building a platform to help redesign the music economy, enabling artists and labels to earn revenue according to how people listen, rather than how they buy," said Last.FM's other co-founder, Felix Miller. "Now we can offer the arrangement to unsigned music creators too. For the first time, anyone can upload tracks and get paid when those tracks are played. It's a whole different model - one that benefits the artists, labels and advertisers - but most of all the listeners."

The service is available now in the US, UK and Germany and will be rolled out internationally in the coming months.