Let's focus on this book. Anastasia Steele is a very young and naïve student who falls immediately in love with Christian Grey, a multi-billionaire young man who has some odd views about sex and women. When Anastasia is offered a contract to become Christian's submissive, so he can be her Dominator, Anastasia cannot decided what to do. A normal woman would have run away, but this character lacks of any personality trait that can make her use her common sense. So the story tells you the doubts and thoughts of Anastasia about Christian's proposals, while they have all kind of weird and hot encounters. Some of them are even too weird as to be believed to be real. The ending was a bit unexpected, especially because the character of Anastasia suffered a dramatic change.
The author says that she started writing this book as Twilight fan-fiction. I believe her. The book is packed with references and parallelisms with the story and the characters in Twilight (without werewolves and sparkling vampires, thanks heavens!). I won't tell here the similarities, since I would spoil lots of things.
Apart from all this, I have to say that I could sense a story behind the story that was being told. I would have liked to see more of the inner thoughts of Christian Grey. I mean, he is obviously a tortured man. A man who tries to fight his inner demons every day. I kept on reading because I really hoped that I was going to see that story developed. Why is Christian Grey like this? Why does he seem to despise women? Why does he get pleasure only by being a control freak and being a Dominator to women? I find his character to be a fascinating one, while Anastasia is just as annoying as Bella Swan, from the Twilight saga. She cannot make up her mind just once in the whole book. So I felt curious to read the continuation of this story.
So now you should go and read the review of the second book in the trilogy :D