I think the approach is different, so it results in a different experience. In Pandora, your only option is to start a station by seeding it and that is saved

I think the approach is different, so it results in a different experience. In Pandora, your only option is to start a station by seeding it and that is saved as a permanent artifact. The perception is that you've created something, but your only way to mold it is to rate songs. I tried for a long time to create a station for "Female Vocals J-Pop" but could never get it to stop playing male vocals. On Spotify, things are presented as a playlist. They have a set number of songs and the idea is that they were curated by someone -- Spotify or another user. When you seed something from an artist or song, it creates a playlist with a limited set of songs. That playlist barely stays accessible through the UI unless you choose to save it, and then you have access to curate it.