As previously rumored, Spotify has today officially launched a new, free mobile listening option for its subscribers, as well as confirming an earlier report that rock legends Led Zepplin would be joining its library. At a press event in New York, Spotify has detailed the new mobile service that comes with a couple of conditions; namely ads and shuffling.

Naturally a free music streaming offering like this will offer in-stream advertisements, not unlike the free desktop offering or iTunes Radio's free tier. Also, free subscribers will be able to listen to whichever artists they desire so long as they're happy that they're shuffling through the artists catalog. Thankfully you'll be able to skip tracks you don't like, and add things you're more fond of to playlists.

The other big news is of course the arrival of Led Zeppelin. Famously missing from online music streaming services, Zeppelin only entered the iTunes Store back in 2007, and so todays news is massive for fans, and for Spotify customers. 2 albums from the catalog will be launched per day this week, starting today with Led Zeppelin and Led Zeppelin II.

Things don't end there though, as Spotify has also announced 20 new markets for its services launching today across Europe, South and Central America.

Things continue to heat up in the streaming music space, and Spotify has once again shown its hand as being one of the biggest dogs in the yard. How does any of this fit for you? Will it convince you to sign up, or switch from your current service of choice?

Source: Spotify (Twitter)