There’s a world of possibility in telling me more about my own listening habits. If I could choose only one feature to add to Spotify, it would be play histories. When was the the first time I played a song? When was the last? When did I first add an album to my collection? How many times have I played it? Given my listening history, how likely am I to like a new album? How often do people with similar histories play a given album? How long did it take me to play one album twenty-five times in comparison to the last album I played that often?