Spotify
 

Have had my invite for a few weeks, been using it on my PC as I have not felt the need to pay for the premium membership.

Music streaming:
Streaming music has been decent quality for listening at work, whcih is where I mostly use Spotify. Advertisements have popped up about every 6-8 songs on average which is not bad. So far the ads are not tailored towards anything specific, they are completely random which is not bad but can be ignoring. Wish I could pick what I want to hear ads for, like specific genres or technology or even cars.

PC Program:
The program is fairly lightweight and really does not bother me when using other intensive programs. Managing playlists, finding music, etc. is very quick and has a layout like any other media player. The only negative I would give the program is every so often I will tab back to the program and a full page advertisement is covering everything up and I have to close it to access anything. Not a huge negative, but it already has a sidebar for ads which I think is enough.

So far I would rate this as a solid upgrade to any other services currently available, for the free version. Need to decide if no ads or streaming on other devices is worth paying for.

Not familiar, this some competitor of slacker and pandora?

Spotify has landed in the U.S. Sign up to get your invite now - Spotify

On Demand Music Site - Millions of Songs - Online Music - Spotify

No, Pandora/Slacker are internet radio, this allows you to search for any song, album or artist and build playlists. Premium service has two levels, remove ads and the other removes ads, allows for offline listening and other stuff.