It analyzes Christian Grey and Anastasia Steele. Their past, their reasoning, their journey within the book.
It relates the story to real life situations and couples dealing with sexual addiction.
Here is the link: http://www.lifestartherapy.com/fifty-shades-of-grey-why-unhealthy-sexual-addictions-hurt-both-men-women/#more-1396
I keep starting to write a little synopsis, but really you just need to go and read LifeStar's article.
Relationships like the Grey/Steele one are very real and serious. It isn't something that should be taken lightly.