Spotify has 500,000 premium subscribers

"Spotify CEO Daniel Ek has told Music Week that the service now has 500,000 paying subscribers, as it prepares to roll out in the US and Japan.
The company's £9.99 Premium sub allows users to access unlimited music via the Spotify desktop client and a mobile app, which is currently available for iPhone, Android and Symbian.
“One of the unique assets and the reason why we have more than half a million people paying £9.99 a month for the [premium] service is because they actually use it as their primary media player," said Ek, adding that Spotify's aim to become “the music platform on the internet where you manage your music and then consume it on any device you want."
The recent introduction of a £4.99 PC-only sub has actually driven people to the Premium tier due to its mobile element, said Ek."
Source:  Mobile Entertainment, 20th July 2010