Why are Last.fm's features unavailable to Banshee users who don't subscribe to the service?

Whenever I try to do anything other view my Last.fm profile in Banshee, I am confronted with the following message at the bottom of the inteface:

Failed to tune into station: Stations are only available to paying Last.fm subscribers

These are features I've been able to use in both the Last.fm client from the Software Center and the Rhythmbox plugin. I can also go to the website and listen there. What gives?

Update: To clarify, I have a Last.fm account, but am not a paying subscriber.

Following a link in the answer provided by DoR, it seems Last.fm changed the structure of their service to be restricted outside of the US, UK and Germany, but I am in the UK so this still just as confusing.

Banshee uses a newer version of the Last.fm API which requires you to be a subscriber, https://bugzilla.gnome.org/show_bug.cgi?id=541227. Rhythmbox uses (or did anyway) a deprecated version of the API that did not require you to subscribe to Last.fm.