There's a point at which parents get so desperate they sell whatever they can to make ends meet, including their daughters.

I was in Cairo, Egypt, last week, and this topic came up as I was talking to some Egyptians at my hotel.

An acquaintance named Ahmed was looking at his Facebook account on a small netbook computer on the check-in desk, when he said, "She's in Africa."

A flurry of Arabic went back and forth between Ahmed and two other men before the story was eventually explained to me. Ahmed had been dating a girl from rural Egypt who came to Cairo after the revolution to earn money to send to her family.

Making ends meet for women and single mothers is not easy in Egypt. Robert Johnson/Business Insider

The girl fell into prostitution, Ahmed said. And he quickly made it clear she floundered at the job: she was unable to demand payment and allowed men to do whatever they liked. It was an ugly tale.

Even worse, the girl had disappeared and Ahmed hadn't heard from her in months, until that morning on Facebook. That started a conversation about prostitution in Cairo, which they all said had blossomed following the revolution.

Prostitution in Egypt is a good indicator of wealth inequality. I found that not only does prostitution seem to have expanded following the revolution, it appears to have settled into stark social and economic layers.

When young men don't earn enough to get married, physical intimacy with women in their network of friends is out of the question. If a young man wants to have sex, he can go to a prostitute. These days, the least expensive girls are Egyptians who frequent certain coffee shops and apartments dedicated to that purpose.

At about 100 EGP (US$13), an encounter is something that most employed Cairo men can pay, but it is very expensive, about half of what many bring home each week.

My friends at the hotel explained that its selection of prostitutes is far beneath the Marriott's, where foreigners stay and have their pick of beauties in the hotel's casino.

That is indeed what I saw when I went to the Marriott. After about an hour of playing nickel slots, I managed to cash out the 20 bucks I'd put in the machine and leave with a good sense of the place. Running the spectrum of hair color and body types, a floating array of available females mingled about and seemed available to whomever might be interested.

One would saunter past a man, stop, turn her back to him, and look over her shoulder for eye contact before moving on. A handful sat at the bar, mostly in pairs, before one drifted off to be replaced by another.

Marriott main entrance. Robert Johnson/Business Insider

In a set of chairs to the side of the casino entrance sat a younger, better-dressed pool of girls. They were different: they had arrived with men on the casino floor or they simply belonged in a different price range.

I left and went to the restaurant down the hall to wait for my ride. Inside the Billiard Bar, I thought, was the wife of a gambler or a guest of the hotel. She was the only one in the place aside from the bartender, and it didn't occur to me anyone would be working the empty room. But I was wrong. After a few minutes she was at my table saying yes, she worked at the hotel. "Americans always figure that out so fast," she told me.

Over her most recent bottle of Stella, "Megan" asked me how much I'd pay for a night out with an American girl at a nightclub. Looking at my watch and wondering where my driver was, I said, "One hundred dollars."

She threw her arms in the air, brushed black hair from her face and leveled her green eyes at me.

Guard gate entrance at the Marriott. Robert Johnson/Business Insider

"I don't believe you," she said, in a slurry of Arabic flavored English.

I told her it was true, that I was a poor American who wasn't even staying in the hotel. "All Americans are rich," she said. Unsure if I was being serious or simply negotiating, she ordered a shot of tequila and I filled in some blanks.

Megan said her mom left her father when she was 14 and he had wanted nothing to do with her. Alone on the street, she fell in with a man of her own, had a baby, and got married before her man left her.

This is common enough story in that part of the world, and it was impossible to say if it was true. But she teared up. "My mother cared nothing about me," she said softly.

But then she threw her head back and said she didn't care, didn't want to talk about her life, and only wanted to have fun. She normally received $400 per client, she said, though more was not uncommon.

Only once had she not gotten paid. That night, she gave her last hundred dollars to hotel security, had the man beaten up, and walked home. She had no money for a cab, but she said it was the finest stroll she'd ever taken.

She was sitting in the velvet wallpapered bar, empty but for Frank Sinatra's voice, because as a local she couldn't enter the casino. The girls by the entrance were for high-rollers, she explained with a mix of bitterness and envy. They were there for sheiks who would think nothing of dropping ten grand on a good time.

My borrowed phone lit up. I looked down and explained my ride was waiting out front. After an awkward farewell, she settled back in the booth to finish her drink

Marriott pool area. Robert Johnson/Business Insider

I went back to my more modest hotel and explained to the guys there that the women of the Marriott were nothing special.

I'd promised I'd stop by the Four Seasons Giza, so the following day I did and talked with the poolside bartender about my Marriott experience. Not to be outdone, he told me how it was handled at the Four Seasons.

The main seating area of the Four Seasons Giza. Robert Johnson/Business Insider

He told me to use my Bluetooth to scan other users and see what came up. The names that appeared left little doubt as to their owners' intent. We found "Sensual," whom we watched ride down an elevator, sit with two men, and leave. An Arabic phrase indicating lonesomeness and availability, as well as other less conspicuous names, lit up and dropped off over the course of 10 minutes or so.

Four Seasons pool area. Robert Johnson/Business Insider

With hotel occupancy down to 15 percent since the revolution, bartenders will tell guests they don't even know their hotel's darker secrets. The rooms at the Four Seasons start at a couple hundred dollars a night, and I assumed the girls likely charged about the same as Megan. The bartender then gave me directions to another two locations where I'd find different selections at different times.

The first Bluetooth search pulled up Sensual, who wore sequin pants, and enormous amount of perfume and very tall heels. Robert Johnson/Business Insider

Prostitution is illegal in Egypt, and charges against women are no joke. The men involved, meanwhile, basically walk away scot-free.

Back at the hotel, a quick web stats search showed a long list of websites devoted to the selling of sex in the city of Cairo. From about €350 (US$450) per hour to multiples of thousands for overnight stays or two-girl evenings, the demand seems clear.

As unseemly as all of this may be, it's still better than the bogus wedding certificates the country now issues to wealthy Gulf men who "marry" girls as young as 13 straight from their parents homes, and whisk them off for a brief "honeymoon" before dropping them back off with a handful of cash.

Called "Summer marriages," these arrangements are merely another way desperate Egyptians are forced into the unthinkable just to get by since the revolution.