Missed in the CES announcements spree earlier this week was Pandora‘s latest audience metrics, for December 2012. The personal radio service reported 67.1m active listeners at the end of December, up 41% year-on-year. Those people listened to 1.39bn hours on the service, up 54% in the same time period, with Pandora now claiming a 7.19% share of total US radio listening, up from 4.71% at the end of 2011. Meanwhile, CEO Joe Kennedy has been talking content costs, and specifically about how they’re much more amenable to Pandora’s business model in Australia and New Zealand, where it relaunched last year. Kennedy told a tech and media conference this week that content costs won’t be more than 25% of revenues in both countries – much more “conducive to the creation of long-term value” than the 68.4% of revenues taken up by royalty payments in the first nine months of 2012 in the US.