Actually, this isn't quite correct. At least, not for a station I've been listening to for the last few years (3-4). It started out based off of OK Go, and has continuously introduced me to new music that I either like or dislike (it does keep trying to get me to listen to nordic death metal). I've learned about a lot of new bands, and have actually managed to develop a (much more accurate than my previous) sense of "current" music.

Maybe Pandora's model changed, but the one thing that set it apart from other platforms is that its music recommendation is not based on 'other music that people like who also like this track/artist', but rather on a number of properties of the track itself.

As a result, you get recommendations that are musically similar, but often new and unexpected.

This is why I love 'I'm Feeling Lucky' on Google's radio stations.