Source: http://gizmodo.com/5500674/exclusive-first-look-at-slackers-excellent-on+demand-music-service
We first caught wind of Slacker Radio's plans for a subscription on-demand music service a few weeks ago, and it sounded vague but promising. Now, having seen it in action, I can say with certainty that it's loaded with potential.
What Slacker's planning to release in the coming months is a fully browsable on-demand service that puts its entire catalog of nearly three million songs at your fingertips. Using Slacker's internet radio interface as a jumping off point, you can sort through tracks, artists, and albums within a genre either by popularity or alphabetically.
Once you've found something you're interested in, you're greeted with artist information, and the option to either play the entire album or to select a specific track.
Even better: you can also create playlists that can be accessed whenever you want for however long you want. As of now there's no planned limit to playlist length, although there will inevitably be some (very high) cap due to caching limitations.
Slacker will also apply its radio technology to your playlist if you so choose, intelligently ordering tracks like your own personal DJ. And a separate "My Favorites" list is automatically kept based on how you rate songs through the course of using Slacker.
Slacker's on demand service will also feature something generally sorely missing from internet radio: a Back button that lets you listen to previous songs in a given station's rotation or in your playlist. It may seem like a minor point, but it's an essential one for the fully on-demand experience that Slacker's promising.
The interface I saw today was a little sluggish at times, but it's still in the late development stages and the person I talked to was confident that it would be faster by its release. There aren't any specifics on pricing yet, unfortunately, other than that it will be "very competitive" with other similar offerings.
Slacker users will only need to download one app that will work for every piece of service. That is to say, a free option will still be available, but free Slacker users will be able to upgrade at any time to the on-demand subscription model.
All in all, Slacker's is a wonderfully intuitive approach to on-demand internet radio, and really does give you an incredible music library to play with as you please. Is it worth the money? That depends on what it'll cost. But assuming the pricing is halfway reasonable, there's clearly a lot of value in what Slacker is offering.