Pretty sure Spotify's Discover Weekly works specifically because of the constraint they set up for themselves. It's updated once a week, and there is a finite number of songs in the list. With other services, people turn on the "recommended" station and expect an infinite stream of music that they will like.
Aaron Parecki is the co-founder of IndieWebCamp,
and maintains oauth.net. He is known for having tracked his
location at 5 second intervals since 2008, and for co-founding Geoloqi, a location-based software company
acquired by Esri in 2012. His work has been featured in Wired, Fast Company and more. He was featured in
Inc. Magazine's 30 Under 30 for his work on Geoloqi. He is currently working as the
CTO of Esri's Portland R&D Center.