Spotify gained a million new users after integration with the Facebook homepage ticker

"At f8 last Thursday, music services such as Spotify, Vevo, Rdio and Mog gained the ability to publish the listening activity of their users to Facebook’s new home page Ticker. The exposure to the friends of their users through the tickers has led to big gains for some music partners.
Most significantly, Spotify has gained one million new monthly active Facebook-integrated users since f8 to reach 4.4 million MAU. It spiked from 1.12 million to 3.25 million daily active users the day after f8, and appears to be settling back to roughly a quarter million new DAU. Rdio, MOG, and Deezer have also seen significant gains in their numbers of Facebook-integrated users."
Source:  Data from Inside Facebook, collected from looking at app users, reported on 26th September 2011