"It's as easy to fall in love with a rich man as a poor one." Some elderly aunt probably offered that advice at some point and you probably dismissed it. You vowed to marry only when you found The One, and his bank account would not be a factor. That's certainly the prevailing view of marriage, American style, in 2009. It's supposed to be a love match between two people who somehow sense that they are meant to be together forever. Admiring her intended's bottom line (the financial one, that is) automatically makes a woman a gold digger. Even the late Anna Nicole Smith, no rocket scientist, understood that being accused of marrying just for money was an insult. She married oil tycoon Howard Marshall Smith when he was 89 and she was 26. "It just so happens," she once said, "that I get turned on by liver spots."

In June, the prime month for weddings, it may seem heretical to suggest that romantic love is not the only requirement for a successful marriage. But that's what the authors of a provocative new book advocate. In Smart Girls Marry Money,Elizabeth Ford, a news producer, and Daniela Drake, a physician, argue that despite the gains women have made in the last few decades, we still earn considerably less than men (especially if we are mothers). A husband's paycheck is still critical. "We gals just haven't come far enough or fast enough," they say. "We know it's important to take the long view of things, but as we've heard said, in the long view, we'll all be dead."

Then there's divorce. Ford and Drake say that since women suffer economically much more than men when they get divorced, snagging a good provider is ultimately critical to an equitable settlement. And if current statistics hold, half of new couples are likely to eventually split up. Given that depressing reality, Ford and Drake say that a husband's earning power is a more important indicator of a woman's future happiness than his cute smile. "If the marriage crashes," they write, "it's the women who are exposed to an extremely high risk of poverty." They urge their readers to look for a Mr. Right "who just happens to be Mr. Rich."

While we're not quite ready to give up on the romantic ideal, the book did get us thinking about why a woman chooses a particular mate. As Ford and Drake point out, romantic love is a relatively new concept. Throughout most of the last 10,000 years, couples got together for economic reasons or for duty to their family. And much of the time, it was the families who arranged the unions. The idea of a bride and groom actually choosing to be together was considered disruptive, says anthropologist Helen Fisher in her book Why We Love. "This mercurial force could lead to suicide or homicide," she writes. "Even worse, it could upset the delicate web of social ties."

Arranged marriages are still popular in many cultures, and there are some indications that the appeal of these unions might be catching on, even in 21st-century America. Both Fox and CBS are reportedly developing reality shows based on the concept. In the Fox version, called I Married a Stranger, friends and family select a spouse from a pool chosen by producers. The CBS show, Arranged Marriage, tracks one couple through the process, while Fox will feature a different couple each week. Perhaps that's a logical next step when you consider the fact that the so-called love matches on shows like The Bachelor and The Bachelorettehave rarely led to long-term relationships, much less the altar.

A marriage based on more practical considerations can ultimately become a loving one. But in the past, that didn't really matter. As long as a couple fulfilled their obligation by staying together, one partner (usually the male) could look elsewhere for affection. Today we place higher demands on marriage. Spouses are supposed to be true to each forever (and with increased life expectancies, that can mean 50 or 60 years for the lucky ones who don't divorce). So the choice we make in our mid-20s (the average age of first marriages in America) has to be a pretty smart one.