Pandora's free music service is admirable, but if you're a mobile Pandora listener with extensive music tastes, you may want to consider the paid alternative as the company shifts to limiting the number of tunes you can hear per month.
In a blog post, Pandora founder Tim Westergren notes why they've made the change, citing increasing per-track royalty rates as the reason behind the change. According to Westergren,
Most of you reading this will never hit the limit. In fact, it will affect less than 4% of our total monthly active listeners. For perspective, the average listener spends approximately 20 hours listening to Pandora across all devices in any given month.
Westergren notes that any user who is about to reach the 40 hour limit will receive alerts warning them that they are about to hit the listening wall.
A note to our listeners [Pandora]