Candice Kashani graduated from law school debt-free this spring, thanks to a modern twist on an age-old arrangement.

During her first year, she faced tuition and expenses that ran nearly $50,000, even after a scholarship. So she decided to check out a dating website that connected women looking for financial help with men willing to provide it, in exchange for companionship and sex -- a "sugar daddy" relationship as they are known.

Now, almost three years and several sugar daddies later, Kashani is set to graduate from Villanova University free and clear, while some of her peers are burdened with six-digit debts.

As the cost of tuition and rent rises, so does the apparent popularity of such sites among students. But are they really providing financial relief, or signing women up for something more exploitative and dangerous than debt?

Kashani believes such sites are a "great resource" for young women, but others say these arrangements smack of prostitution and take advantage of women in a vulnerable situation.

Lynn Comella, an associate professor of gender and sexuality studies at University of Nevada Las Vegas, said that it is not unusual for students to turn to sex work such as stripping, prostitution or webcam work to pay for school. But the sugar daddy sites are relatively new, and she says not entirely upfront about what they are really about.

These arrangements are more vague than prostitution-- there is an expectation of material benefit but it is not always specified and sex is not guaranteed.

Ron Weitzer, a professor of sociology at George Washington University and criminologist with an expertise in the sex industry describes it as "prostitution light."

"Sugar Daddy" arrangements have existed for ages, and it's unclear if they are becoming more common because the phenomenon is not well studied. But experts say at the very least the internet has made these transactions far easier to arrange and negotiate. "It allows you to hone in on what you want," said Kevin Lewis, an assistant professor of sociology at University of California San Diego who studies online dating. "You could argue it is just making the market more efficient."

Kashani says she sifted through many potential suitors before finding one she clicked with. She says she considers her sugar daddy one of her best friends and that they care deeply for each other.

"The people who have a stigma, or associate a negative connotation with it, don't understand how it works," she says.

But unlike most relationships, she is paid a sizeable monthly allowance that helps her pay for school.

U.S. undergraduate students last year finished school with an average of $35,000 in student debt -- a figure that has risen steadily every year, according to Mark Kantrowitz, a financial aid expert. The average graduate debt load is $75,000, and some longer programs force students into much deeper debt.

Many students say their loans don't cover the cost of living, and with rent skyrocketing in most major cities, they are left scrambling to make up the difference.

One graduate student at Columbia University in New York had a scholarship that covered almost all of her tuition, but not her living expenses. She spoke on the condition of anonymity because of the potential impact on her job prospects. She tried to make do -- sharing a room with a classmate and working a minimum wage job, plus any freelance work she could get. But still she struggled to pay her rent and utilities, and her grades suffered.

"That's just not why I am here," she said. "I wanted to find the most amount of money I could make for the least amount of effort."

So she found herself surfing Craigslist and Backpage.com and later, SeekingArrangement.com, the largest of the sugar daddy websites. Now she has two sugar daddies, one she sees occasionally and another who is more like a conventional boyfriend, except that he pays her a monthly allowance and helps rent her an apartment closer to him.

SeekingArrangement.com said it is most popular in Los Angeles and New York. The average rent in both areas is well over $2,000 a month, according to Zillow research.

The Columbia student says she plans to continue "sugaring" after she graduates to buy herself time to find a more traditional job and remain officially unemployed so she can defer repaying the roughly $70,000 in loans she had already racked up.

"There is a lot of moral panic about it," she said. "But what are the real estate and academic funding situations that led to this?"

Brandon Wade, creator of the site, touts it as an "alternative to financial aid" but says the company did not set out to target students when it launched in 2006. It stumbled on this niche and began in 2011 offering students a free premium membership, which usually costs $30 a month. It charges sugar daddies $70 to $180 a month, depending on the membership level.

Seekingarrangement.com also offers to connect same-sex couples looking for such arrangements, or "sugar mommies" for men. But the male-female "sugar daddy" dynamic makes up the bulk of its business.

It's difficult to pin down exactly how many students are involved in such situations, because they are private transactions. And it's a niche rarely studied by academics.

SeekingArrangement.com says student users on the site jumped from 79,400 worldwide in 2010 to 1.9 million this year and students make up one-third of its users. And while it sees thousands of signups on any given day, the company says enrolment jumps during August and January when tuition is typically due, sometimes to more than double its normal levels.

Women who have used the site report experiences that run the gamut -- from respectful chaste dates all the way to aggressive solicitation online, even though it is forbidden on the site. Sex is not guaranteed although most users say it is implied. The company says a few arrangements have even led to marriage, although it is rare.

Some of the women say they feel respected and cared for, but remain aware that it is an arrangement, not traditional romantic love.

"It benefits me in many ways -- we have a healthy relationship, we travel together, I'm able to enjoy the city more," said the New York graduate student.

Still, she said, it is a job.

"It does kind of rub me the wrong way that some people don't see it as sex work," she said.

Comella warns that unlike sex workers, many women doing this put their true identities online, and that could put them at risk. While Seeking Arrangement runs background checks, there have been reports of violence against both men and women stemming from sugar daddy websites.

Kristen Houser of the National Sexual Violence Resource Center says that violence is common any time money is exchanged for sex. "You need to pay attention that there is a power imbalance," she said.

Wade says there are risks inherent in any dating website. He should know; he runs several, including one that allows users to bid on dates and another focused on open relationships. He said he created SeekingArrangement.com out of his own frustration with women. An MIT graduate, he had difficulty meeting women and realized a site such as this would highlight what set him apart -- money.

"Money and sex are things that people want," he said. "I think the controversy comes into play on seeking arrangement because we are so upfront about it."