Bumping this up because I saw a link to an article about 50 Shades where the author, Katie Roiphe, surmises that the reason why the book is so popular is because women have a secret desire to be dominated. Basically her argument is that as women have gained more equality in the workplace, in dating, in sexual relationships and in other realms, that they feel a need to still be submissive. One way they can still be submissive is by engaging in BDSM and be submissive in the bed.
http://www.thedailybeast.com/newswee...fantasies.html