It is a lesser known fact that the MPAA gives films higher ratings for sexual content than violence. This sends a message to American parents, convincing them that it is more acceptable to kill another than it is to physically love another.
One of the main reasons that directors have the MPAA rate their films is so that they can be advertised successfully and therefore make a profit; six of the largest film industries also control 90% of the media. However book advertising has little to with that same kind of controllable media. Word spreads through independent book stores, the internet, and word of mouth, none of which is powered by any of the top film-controlling businesses. Therefore it would be unnecessary for books to even want ratings, let alone need them. Despite how useful the ratings may or may not be to parents, there is no real reason for books to necessitate them.
On the topic of whether or not they would be useful to parents or not, I say, simply this: Your children already download whatever they want. Movies, music, and books are included. If they want to get their hands on a specific book, they will get it. Passing a law saying that they must be seventeen or older to read a book with a gay sex scene in it will not prevent them from reading it.
The reasoning behind the system is unfathomable, but it does prove that the MPAA’s rating structure is devastatingly flawed. Let the original story tellers keep their sanctity. For these reasons alone, there should not be a rating system put upon books.