Pandora Milestone: The 10 Billionth Thumb

"On Sunday, April 24th at 4:46pm, "Ridin' Solo" by Jason DeRulo received Pandora's 10 billionth thumb," crowed a proud Tim Westergren on the company blog. Pandora's thumbs – unlike Facebook's Like which only points upward in approval – can be directed up or down as users fine tune their music choices. By comparison, it would take the fans of 303 Lady Gaga's (33 million Facebook likes) to match the engagement with Pandora's thumb.

Of course, while tempting to measure Pandora's thumb against Facebook's Like button, it's not a particularly usefull comparison. Users thumb many songs during each Pandora session and Like many different pages and posts while browsing Facebook. The top 30 pages on Facebook each have between 20 and 40 million likes.

But 10 billion thumbs is tremendous proof of engagement by any measure. "Of the many milestones we've hit over the past 6 years, this is perhaps the one that makes us most proud," said Westergren.

As of March 2010, Pandora had 700,000 tracks in its library and 48 million users who listened for 11.6 hours per month on average. The company is currently  preparing for an IPO later this year.