I think part of the reason it continues to sell as much as it does, is it's a timeless record. Timeless meaning, the production and music doesn't sound dated and the themes and concepts explored in the lyrics are relevant to everyone, no matter when they listen to it. Everyone goes through a period where the music on that album speaks to them, gives them purpose, explains things to them that they are confused or unsure about. I can't think of any other album by any other artist in which you can say that.