Adele’s new album, 25, has broken the music industry’s record for most albums sold in a single week. And the week is barely halfway through! The record, released on Friday, has already sold more than 2 million copies. Only one other album has done that since Nielsen began tracking sales in 1991: N*SYNC’s No Strings Attached, in 2000. What does Adele’s success tell us about her unique appeal and the music industry in general?