I bought this book for my 13 year old, but read it myself first, just to check it was suitable. I would recommend other parents do the same, as it will really scare some kids. You'll know whether your son or daughter is ready yet.
Having said that, quite honestly this is the book that every teenager SHOULD read. It pulls no punches when it comes to what this creep intends for these kids - and I feel that by the time they're teenagers, they need to know this. Just a moment of carelessness, of 'going with the flow' because that's what your mates are doing, or not checking because you assume someone else is, and anyone could find themselves in this kind of situation.
Then there's the thriller aspect, the chase. OMG, it was seat-of-the-pants stuff! I couldn't sleep until I finished it - and neither could my daughter. We were completely gripped!
I think this book is a real rite-of-passage read for young people who are hitting their teenage years. It's not suitable for younger kids, but the issues are definitely ones that older kids/younger adults should be confronting.
10 out of 10.