First they went to a movie together. Two women—a 30-year-old and a 50-something. Total strangers. Totally platonic. And the older woman paid in advance, so there was no awkward exchange of cash.

They saw Avatar. Afterward, they went out for hamburgers. They talked about the movie, about the older woman’s grandchildren. It was a nice time. A three-hour outing that netted the younger woman—we’ll call her Sarah—a tidy $100. That’s Sarah’s rate on RentAFriend.com.

It was a matter of time, right? Friends for sale online. It’s the sum of our modern equation: Community decline + Facebook + loneliness + 80-hour-work weeks + anxiety + the Great Recession + PayPal = RentAFriend.com.

There are 108,000 friends for rent on RentAFriend, site founder Scott Rosenbaum says. It costs nothing to list yourself for hire.

It costs $24.95 a month, however, to shop for friends. There are currently 1,200 paying members, Rosenbaum says. The site is five months old.

Sarah, who doesn’t want her real name used in this story, signed up in January. Like most friends for rent, she has an online profile with photos, a description of herself and a list of activities she’s available for, picked from a master list during registration that includes: Wine tasting, skydiving, hanging out, clubbing, video games, phone calls, visiting psychics, e-mail pen pal, balloon rides, working out, gambling and prom dates, among other diversions.

Hourly rates are negotiable. Payments can be made in advance over PayPal. And it’s friendship only—it’s not a dating site, or an escort site, Rosenbaum says. In fact, physical contact is prohibited during outings. Friends you pay, but can’t touch.

The woman who hired Sarah has no family in Las Vegas, and lives alone. It was awkward at first, Sarah says, but also easy—just two women sitting in a dark theater.

A week or so later, she hired Sarah again. She wanted help picking presents for her grandchildren. Sarah works as a nanny six days a week, so she knows what kids like. She interprets unspoken urgencies—the eyes that say, I’m hungry, sick, sleepy, sad.

“I’m able to read people,” she says, “and see what they need.”

We’re lonely. One in four people said they had no close friends in a 2004 survey. Everybody else said they had about two. And that’s down one. In 1985, people reported having three close friends or confidants on average. So in 20 years, we collectively lost a friend, and gained a billion Facebook pals.

Somehow, Las Vegas doesn’t make things easier. Former UNLV researcher Matt Wray found that merely being in Clark County doubles your suicide risk, for tourists and locals. Likewise, when people leave Las Vegas, their suicide risk drops. It’s not just the person, in other words, it’s also the place.

Wray has speculated the same things that defined Vegas during the past 25 years—wild growth, population booms, demographic shifts, transience—came too fast for community cohesion. Almost 1.2 million people moved to Clark County in about 15 years. How many felt rootless and alone, marching in the middle of that steamroller parade?

And how many of those people were contagious? Loneliness, research now suggests, contaminates social networks like a cold. A study published by University of Chicago psychologist John Cacioppo last year showed that loneliness spreads through three degrees of separation. So, if you have a lonely friend, you’re 40-60 percent more likely to feel lonely. If you have a friend-of-a-friend-of-a-friend who’s lonely, you’re still as much as 24 percent more likely to feel lonely.

So maybe Vegas infected itself. The only reason everybody doesn’t feel utterly alone, Cacioppo says, is that we push lonely people to the sidelines—an emotional quarantine. When social groups are mapped, the lonely people are clustered at the outskirts, alone together.

What’s worse, the feeling multiplies itself. In his 2008 book on the subject—Loneliness—Cacioppo writes that loneliness causes people to withdraw, which makes it harder to maintain friends, which makes for more isolation. Soon enough, loneliness is a feedback loop.

We’ve evolved to be this way. Loneliness is an alarm signal, no different than hunger, Cacioppo says. The feeling exists as a reminder to join the group—there’s safety in numbers, and the gene pool evaporates without people to fill it. So why is loneliness so punishing? Because rejoining a group is delicate. When shunned primates try to rush back into their packs, Cacioppo notes, they’re often attacked or killed. The group doesn’t want your infection.

So the onus is entirely in the lonely person—heal your own wounds, or wither.

Going online, by the way, isn’t enough. Lonely people who look for answers in computer-mediated friendships, Cacioppo says, are like starving people eating celery: “It’s better than nothing, but there’s no long-term sustenance.”

Same goes for renting friends, the psychologist says. With no trust, understanding or real affirmation of friendship, a rental friend is just a smoke screen—one that can be harmful if it keeps the lonely person from going out and making real, free friends.

Of course, renting a friend is a last resort. And Cacioppo allows that it may also be a first step—a sign that the lonely person is trying. A sign the lonely person is at least eating celery.

Rental friends are big in Japan. That’s where RentAFriend founder Rosenbaum got the idea. In the past decade, the number of Japanese companies offering professional surrogates—boyfriends, wives, parents—has apparently doubled.

In Japan, however, the booming rental-friend market has been attributed to culture and economy: The jobless are hiring fake bosses to appear employed, divorced mothers are booking pseudo dads to attend their kids’ baseball games, and in one well-publicized case, a man was hired to attend a wedding and deliver a passionate toast about the bride and groom.

We don’t have this degree of high-stakes social pressures in America, so RentAFriend can’t ride on the shame market. Instead, Rosenbaum emphasizes activity partners. People can use the site to hire workout buddies, he says, for less than it costs to have a professional trainer. People can hire someone for dance classes, or pay locals to show them around a new town.

And three college kids, independently, have used RentAFriend to hire fake parents. Adults they paid to come to school, furrow their brows and nod meaningfully while school administrators explained their children had been caught drinking on campus.

RentAFriend is Rosenbaum’s full-time job now. He profits from the monthly fees, and has an affiliate program as well—get somebody to start a paying account on RentAFriend, and Rosenbaum will cut you a commission.

Rosenbaum understands, by the way, that you might see something sad in this. He gets it. But really, he says, it’s not like that. Actually, the saddest RentAFriend story he heard of was actually kind of sweet: When a woman moved away from her mother’s nursing home, she started renting a college girl to visit three times a week in her place.

The second person who hired Sarah was a guy from New Jersey, in town on vacation with a few hours to kill. She met him in a casino, gambled with him for an hour, and left. He paid her $50.

The third person who hired Sarah had just moved to town. He works at an upscale department store, and didn’t have a date to bring to a work party. He hired Sarah, and they went together—she spent four hours with his colleagues, eating cheese and drinking wine. The guy told everyone she was a shopper he befriended. He paid her just over $100. She was home by 10 p.m.

Sarah likes being a rental friend. She’s helping people who want company, she says, and don’t know where to find it. And the two men who rented Sarah are easy to shrug off: One was fighting boredom, the other was maintaining appearances. Neither seemed particularly lonely. Neither really needed a friend.

It’s the older woman sitting in the dark theater that stings, for the very same reason that rental friends seem creepy. It’s taking who we are as a species, our nature to make and need friends, and monetizing it. Renting a dance partner is harmless. Renting a date is insecurity. Renting a friend is gutting desperation—and the drive to commercialize that ache might explain its origin.

“People confuse loneliness with being alone,” Cacioppo says. “They want so badly for the pain to stop they embrace anything.”