When a book is reviewed as often as The Boy In the Striped Pyjamas, it is usually indicative of a great story that enthuses people to debate in public the merits or otherwise. The tell-tale signs of success in the case of John Boyne's efforts are that people have enjoyed the plot and debated the style - I think writers should always challenge readers' traditional comforts and boundaries.
I am in no doubt the author's choice of perspective and prose make this book accessible to many age groups, but I would especially encourage Years 8 and 9 in secondary schools everywhere to read, study and enjoy.
A wise reviewer has suggested readers should avoid the synopsis on the front and back covers and I agree wholeheartedly with this assertion. John Boyne has written a wonderfully provocative story that encourages the reader to experience an important historical period through the eyes of a nine year old boy. Learn, as he does, how his world is changing and what matters to a young boy through relationships with the family, friends, perceived strangers and the boy in the striped pyjamas.
Try and avoid the spoilers and jump straight to page one, it's an easily accessible read and you'll probably have it finished in a couple of days. For me, it doesn't make it any less enjoyable.