Last week's Thursday saw Mark Zuckerberg present a ton of new things at the Facebook developer conference f8 that will hit Facebook in the coming months. One of the additions, that was immediately enabled was the deep partnership with Spotify. For those who love to listen to music in a social way, this is heaven. You're able to dive into your friends' music habits whenever you're in Facebook. There are a couple of downsides to this and the most important one isn't the fact that your Facebook stream is a flush of Spotify updates. It's actually the fact that with the integration - Spotify has disabled any other sign-in method and now requires new users to have Facebook accounts. This is a huge gamble for the Sweden based music company that could backfire on it.
The big picture with Google and Facebook, mainly, is that both companies are building huge platforms that they wish other companies would leverage. This would allow the two giants to "listen in" on what you're actually doing with these 3rd party applications (and then again in return build their presence).
And it is exactly this that has already angered many. As soon as Spotify's answer on Get Satisfaction, the public feedback forum for companies, reached the public, people have been canceling their subscriptions on Spotify referring to the fact that the recent change in login methods drove them to do it.
While new improvements and changes always shake a few people and put them off so much as to leave a service for the changes - partnering this deeply with Facebook could see a bit of an exodus from Spotify. Many of the first comments on the blog post announcing the partnership were supportive, but then immediately people wanted to know if this was coming for other platforms, mainly Google+.
On the other hand, Ek & co most likely have weighed the alternatives here. A deep partnership with Facebook is a great way for them to leverage their user base and grow it from a lot bigger pool of users.
From outside it mainly looks as Spotify is definitely putting all its eggs in the Facebook basket. Then again, if you want to continue fighting to maintain your position at the top - you're bound to anger some in the process of doing so. Ironically, "you don't get to 500 million friends without making a few enemies".