My wife says reading those cheap romance novels sometimes gets her in the mood for making love. I find this very hard to believe. They're so ridiculous and have nothing to do with reality. We would be inclined to take your wife's word for this, and add that there are probably many more women than you might think who feel the same way.
Romance novels can provide an escape from the often difficult realities of everyday life.
Some background information on romance novels might help you to understand. These novels often uphold traditional norms in our society, such as viewing premarital and extramarital sex as undesirable behaviors. There are some novels that reflect the heroine's decision to have intercourse, but only with the man who has committed himself to marriage with her. The explicit language describing sexual encounters or parts of the body that is often used in male-oriented pornography is not used in romance novels. Instead, more flowery language is used.