im going to have to disagree here. ive trained my google play by hitting the like button on songs i like. My music taste is wide ranging but often quite selective within a genre and its really blown me away with how good its been with providing me with subtley new music i.e just similar enough to interest me but different enough that i dont get bored. This also feeds into my weekly 'new music that i might like' menu. I really dont get suggested anything thats in the charts anymore much to my pleasure!
