A good read if you just want a fast-paced thriller. I think even Paula Hawkins will be surprised by this book's success as it isn't particularly well written. The characters are very stereotypical and, frankly, a bit sexist. All of the women are neurotic and all of the men are broodingly handsome and they only have to go near a woman (any woman) for her to throw herself into his arms. The plot line is quite good but is spoilt by the inevitable surprise on every page. Suspense is not built, it is thrown at the reader.
Still, I agree with some reviewers that it is a hard book to put down. As a debut novel, it's okay but I suspect Paula Hawkins will do better next time.