I have a playlist of all of my favorite songs. Just from browsing around Spotify for a little I found a playlist that had about 70% of the songs in my playlist in it. I soon discovered that I loved the majority of the songs in this new playlist that I didn't already have in mine. I have discovered a lot of new music this way, but it is difficult and time consuming to find new playlist similar to mine.
I think it would be awesome to have the ability to discover new playlist that contain a lot of the same songs as my own playlist. This could be done with a "Search for Similar Playlists" feature that allows users to drag multiple songs or playlist into a search feature that locates playlists others have created that have a high percentage of similar songs in it.
We're keeping this as a 'Good Idea' for now. Please know your feedback is reaching the internal teams at Spotify, and they're aware of the votes around this idea. We'll continue to check out the comments here too.
Just as a heads up, be sure to check out the 'Create Similar Playlist' option on the Desktop and Mobile apps. You can find it by clicking the three dots on most playlists.