Spotify has already announced its coming to the U.S. and now thanks to a leaked document its inadvertently told people how it will take on iTunes.

This week the streaming music provider made an announcement on its website, ( about its plans to come to the U.S.

Spotify has 10 million users in Europe alone, although most are non-paying customers. The service allows users to find new music with simple search and offers them thousands of free songs. It also has a number of subscription based packages. Its revenue is generated from both subscriptions and advertisements. It shares royalties with record companies and reports indicate in some European countries, Spotify is the music industry's number one source of revenue.

When it officially comes to the U.S., Spotify will have to deal with iTunes, which has long been the top dog in digital music. There are numerous approximations as to how many iTunes users there are in the world but most have it around 500 million. iTunes has been one of Apple's long-standing cash cows. One analyst recently said Apple could see $13 billion in revenue from iTunes as soon as 2013.

All Things D's Peter Kafta was able to find get a hold of promotional materials that Spotify has shown advertisers as to how they plan on taking on this beast. The company has seven different strategy points. Most prominently, it will look to Facebook to help integrate the service into American culture. Facebook chief Mark Zuckerberg is reportedly a big fan of the service. The promotional material says Spotify Social on Facebook will open up the service to potentially 150 million users

Spotify also says the buzz from the launch, which has been two years in the making, will help it gain users. The company says press coverage will be huge and help its launch and it claims to have hundreds of thousands of email addresses waiting to get accounts.

Overall, Spotify has lofty expectations for its U.S. launch. The company says in the promotional materials that it's looking for 50 million U.S. users within the first year.

Spotify did not respond a request for comment.

Follow Gabriel Perna on Twitter at @GabrielSPerna