Spotify uses Facebook exposure to open free streaming to everyone

After several months of keeping its new service invite-only, Spotify took advantage of its spotlight at the Facebook f8 event this week to open its doors to anyone who wants to use the on-demand music service. And they’ll get to do so free for six months.

One of Facebook’s big announcements Thursday was allowing for much more interactivity between users when it comes to media like music services. For example, Spotify users can use Facebook friends to find new music to listen to and even see what friends are listening to in real time. This sort of capability is one that Spotify wants all Facebook users to have, so this is an ideal moment to take down the invite-only wall.

Spotify will now let anyone in the U.S. join its streaming music service by simply signing up at spotify.com. The service will be free for six months with occassional ads for free, but after that Spotify will give you 10 free hours a month or you can sign up for a premium plan. For $5 a month, you can listen to Spotify’s catalog without ads via PCs; and for $10 a month, you can listen to music without ads via PCs and mobile apps for iPhone and Android.

Streaming music services have been making quite a few headlines as of late and the field is getting exceptionally competitive. While Spotify is relatively new, it has done a good job a keeping its profile up against strong rivals like MOG, Rdio and Rhapsody.

Spotify currently has more than 2 million paying subscribers in eight countries, adding about 400,000 paying users since its U.S. launch. The company has raised $120 million so far and is valued at about $1 billion. It recently finished raising a round of financing from Russia’s DST, the investment company that has previously backed Facebook, Groupon and Zynga.