Have you ever had sadomasochistic fantasies? If you are like me, not only have you never had any, but you even view sadomasochism as an exotic and very distant land. Assuming that most people are boringly similar to me, then it is a puzzle how "Fifty Shades of Grey" -- a romance novel in which BDSM (short for Bondage & Discipline, Dominance & Submission, Sadism & Masochism) is the central plot motif -- became a phenomenal global success.

Many commentators have too easily solved the puzzle by calling it a result of and testimony to a mainstreaming of porn culture. What was previously hidden in the stash of magazines under the bed, and now hidden in the private browsers of Internet sites, has become legitimate. But soft-porn literature has been around for a long time, too, and the range of sexually unconventional behaviors is wide. So that justification does not explain why this particular novel, with a BDSM relationship at its center, has garnered such uncanny success. The "Fifty Shades" trilogy has sold more than 10 million copies worldwide, and its rights have been bought in 37 countries, including Germany, where it was published in translation in June. It is flying off the shelves faster than the "Harry Potter" books.

Unsurprisingly, the book has elicited fierce feminist controversies in the United Kingdom and the United States regarding the question of whether submissiveness is a violent or emancipating fantasy for women. But, as a cultural sociologist, I suggest that, before we engage in a discussion about the politics of the book, we should try to understand why it provides pleasure -- of the symbolic rather than sexual variety.

Best-sellers are always a puzzle. Most of the time, no one predicts their success; and yet, once they do succeed, it is as if their success was inevitable. How can we now explain that the new worldwide best-seller "Fifty Shades of Grey" not only succeeded, but did so despite its mind-boggling flaws as a piece of literature?

He's Not Like Other Men

To a sociologist, a best-seller is defined by its capacity to resonate with our social experience in at least three different ways: It contains some very familiar aspects of our social experiences; it addresses -- in a veiled or explicit way -- an aspect of that ordinary experience which is difficult, elusive and a source of constant bafflement; and it offers a symbolic, fantasized resolution to this bafflement.

"Fifty Shades" has the structure of a very conventional romance. The story is set in Seattle and focuses on Anastasia Steele, a college girl who is still a virgin when she meets the very attractive, successful and young Christian Grey. For the first time in her life, she experiences intense sexual desire and finds in him an exceptional sexual partner. Indeed, something sets him apart from other men: He will enter a full relationship with her only if she signs a contract in which she willingly agrees to become his "submissive." That is, she agrees to be beaten, spanked and tied up, to lower her eyes in his presence, to sleep the number of hours he prescribes for her, and to eat the foods and wear the clothes only he chooses for her. In addition to this contract, she is also asked to sign a nondisclosure agreement preventing her from divulging to anyone the nature of their relationship.

With these elements, the book represents a perfect mixture of a very conventional romance with an intensely charged erotic novel centered on a BDSM contract. This is familiar territory. Since the 18th and most definitely 19th century, romance novels have given expression to women's search for love using the pleasurable formula in which the heroine meets an attractive but dark and threatening man who later reveals himself to love and be devoted to her.

"Fifty Shades" also treads on another familiar terrain as it raises the now-obsessive question of the role that free sexuality should play in women's lives. It is a question largely popularized through such TV series as "Sex and the City" and, more recently, through the widely popular HBO series "Girls." Sexuality in its many forms has also become a familiar theme through the process, which some have identified as the "pornification" of culture or the mainstreaming of pornography in culture.

'I Don't Do the Girlfriend Thing'

In "Fifty Shades," the familiar search for love and good sex is used to address the endlessly baffling question that has become a chief preoccupation for psychologists, sociologists, artists, writers and ordinary people: What do men and women want when they are together?

The relationship that progressively unravels between Christian and Anastasia displays their gendered and divided desires: "I don't do the girlfriend thing," he says repeatedly, in addition to, "I don't make love ... I fuck hard." She, on the other hand, is preoccupied with her intense desire for him, struggling to make sense of his aloofness and mood swings as well as her endless self-doubts and surprise at being desired. "His sudden aloofness makes me paralyzed," she thinks. "He wants me?" she asks.

But each wants the same thing: for the other to desire him/her exactly as he/she wants. "I need him to want me like I want," Anastasia tells herself incessantly, whereas he ceaselessly says: "I want you to want to please me." Each wants to remain free, and each wants to enslave the will and the desire of another.

This is indeed the Hegelian conundrum around which modern sexual and romantic relationships labor around, often hopelessly so. This is also why romantic relations have become full of ambivalence (replete with conflicting emotions and desires), of uncertainty (we never really know what their rules are, or what their outcome will be), and of indeterminacy (poised between the casual and the committed, the painful and the pleasurable, the secure and the anxious).

The Promise of BDSM

In "Fifty Shades," these endless conundrums are solved by a sadomasochist contract that at first seems deceivingly like an obstacle to love. Moreover, I would argue that the sadomasochist relationship in general is a highly plausible solution to the complicated and uncertain labors of love for a number of reasons.

• By definition, a BDSM relationship contains both pain and pleasure and thus neutralizes the ambivalence of relationships that alternate between pain and pleasure.

• One of the greatest difficulties of modern relationships is relinquishing one's autonomy to another because, in doing that, our sense of dignity is always at stake. The BDSM contract does the logically and psychologically impossible: It makes one willingly give up one's will and autonomy to another. In that sense, it solves the problem of relinquishing one's autonomy.

• The equality that has been promoted by 40 years of feminism demands ongoing, ceaseless negotiation. The BDSM contract stops the endless bargaining by setting up and freezing caricatured and exaggerated roles and positions. In fact, BDSM makes inequality acceptable because it is consensual, contractual and pleasurable.

• Finally, sadomasochism can take place only between two people who fully trust each other. The dominant partner stops hurting the submissive partner as soon as he or she says the code word. In that sense, BDSM is the very performance of the scarcest commodity: trust.

Against this context, it is our ordinary heterosexual relationships that have become queer indeed: complicated and elusive and impossible to predict and control. They demand an enormous sophistication in our capacity to play many roles, endlessly negotiate boundaries and make sense of our own and the other's ambivalence. If conventional relationships have become queer, then the romance between Grey and Steele suggests that BDSM actually holds the promise of erasing that queerness by giving us access to erotic ecstasy without the anxiety of ambivalence and uncertainty.