Beginning February 15, Last.fm will require a subscription to stream music to your iPhone and it will be ad-free. Here's what Last.fm's VP of production, blog Matthew Hawn had to say:
On the Last.fm website an ad-supported, free-to-listeners model is what supports our online radio services in the US, UK and Germany. In other markets and on emerging mobile and home entertainment devices, it is not practical for us to deliver an ad supported radio experience, but instead, we will migrate to what we believe is the highest quality, lowest cost ad-free music service in the world.