Very difficult with streaming. Rdio used to have a slider to recommend more unusual music. No other service has this that I’ve found. They keep playing the same songs and artist forever.
I find this especially bad with video streaming where a service has a great library but only promotes about 30 titles all categorized under different genres.
I suppose they save on bandwidth if they can get everyone to just stream the same titles.
Plus, it had a persistant queue that could handle single songs as well as albums and playlists as individual items which could be moved freely. Everything I was interested in was added to the queue and I could be certain it'd still be there tomorrow. Sort of like a musical backlog.