Also, because of Taylor's confessional songwriting, albums based on heartbreak/life experiences could smash.
Ed Sheeran's albums, Sam Smith, and to a lesser extent, 21. (Obviously I'm not crediting Taylor for Adeles gargantuan sales, but 19 didn't see half the success of 21. But after Taylor made her initial impact with fearless, Adeles follow up album, with confessional heartbreak tales, smashed on an unprecedented level.)