This is a long, but well-written piece on the attraction of 50 Shades.
Women are as vulnerable as men to lust and porn, just so long as it is produced and marketed in a way to resonates with them. They are the expanding demographic for porn.
And as i have written before here and here, women are the last frontier in the advancement of pornification. The more the porn industry is able to get women to buy in, so to speak, the more any barriers or arguments against its total acceptance will be decimated.