Discover Weekly seems to pull based off of your all time plays. So spotify playlist submission if you decide you want to listen to a genre you don't often listen to for an entire week, that won't be reflected in your Discover Weekly. This isn't necessarily a plus or a minus. For me, I'd rather get music suggestions based on the music I've listened to most recently.

There is a supreme lack of visibility in their process. Understandably they don't want someone else to copy how this works. I would be really curious in reverse engineering their algorithm, but that would involve keeping track of everything I listen to throughout a week (impossible), and I'd have to suddenly become a software engineer(which I'm not), plus Spotify will never release how promotional activity affects this playlist.

The refresh time of the playlist seems to be really arbitrary, and I'm not sure what causes it. I've had my playlist refresh at 2 in the morning on Monday, and I've had it refresh at 10pm on Monday. The inconsistency is rather annoying for those of us who are super habitual beings. UPDATE: I've now noticed that it seems to refresh whenever you restart the client. It would be nice if they had a push setting to alert the user they need to restart the client to retrieve it.