in my case, it is for example play list of music videos. Sometimes I hear a very nice unknown music as series soundtrack, sometimes you manage to find the name of long forgotten loved song. And usually, in the rush of the daily activity, it is simple to "save to playlist" while watching it in youtube.

Then, usually you play the list by itself from random position and order. So I quite often listen to them, but for a playlist of maybe 50 entries, i will just noticed that things disappeared when looking at the "hidden entries" thing.