Pandora has 80m users

"Here are some other stats from the filing.  Pandora now has (as of January, 2011)...
80 million users (up 73.9 percent year-over-year, with a new user registering every second)
800,000 songs
80,000 artists
3.9 billion listening hours for the year ending January 31st, 2011 (up 86% from 2.1 billion the prior year.)
50 million mobile app downloads to-date, in the US alone."
Source:  Data from Pandora, reported by DigitalMusicNews, 11th February 2011