The premise is an interesting one, and quite unique. The narrator is one of thirteen people who Hannah Baker blames for her suicide. Just before overdosing on pills, she related her reasoning on audio tapes, which she then mailed to the first person on her list with instructions for them to successively pass the box of tapes on to each of the twelve subsequent people.
The writing isn't stellar, and I found myself not really believing that, #1, Hannah was actually depressed enough to kill herself (just judging by her tone on the tapes which, while perhaps bitter and alienated, didn't really sound suicidal), and #2, that her thirteen reasons were adequate to put her in that frame of mind. Ok, at least two of the thirteen were pretty harsh, but the other eleven . . . not so much. (Ironic thing is, I bet that is exactly what all thirteen people would have thought, too.) But neither of these things kept me from breathlessly flipping the pages. It's definitely an absorbing story.
The book does have a good message, too, which I hope that any teen reading it can recognize: be vigilant, and be kind.