An unexpected fringe benefit: Many of my clients were talkers, and that wound up helping me out a lot in school. I got top grades in English thanks to all the practice I got with clients. You can study quietly in a library, or you can study while having sex and getting paid for it. Seemed like a better deal to me.

It's really only tourists who look down on us for it. One white woman passed me and an older guy holding hands in the street once and told us that "we should be ashamed of ourselves." But he was satisfying his sexual desires, while I consented and was getting money to save up for a moped. I certainly didn't feel ashamed or abused while hooking; I felt like I was 62 percent of the way to a bitchin' scooter.

Pete Niesen/Hemera/Getty Images Consider it a lay away plan.

You may think that starting work as a prostitute is as easy as dressing sexily and actually accepting those lewd offers the guys are yelling at you anyway. But without a "caller," you'll be lost. Callers are basically those guys who twirl around big arrow signs to get people into mattress stores and pizza joints, but for sex workers. No, they don't dance on the street corners while spinning vagina-shaped signs -- they call out to passing tourists and carefully screen prospective clients. Each one knows what the prostitutes they represent can handle.

Zhang Han Figuratively and literally.

For example: They'll avoid pairing most of us with heavyset people. Many Vietnamese women are small, so a large, heavy man will be a problem. If the client persists and asks for us specifically, they will have to meet us for dinner rather than riding with us straight to the destination. That's not because we hate them -- fat tourists on mopeds are more of a physics problem than a moral one.

xuanhuongho/iStock Editorial/Getty Images "It's a motorbike, not a Walmart scooter."

The established callers all have their own turf, and they'll chase away any unrepresented prostitute they see working their area. Other areas are absolutely filled with moped-straddling hookers already, and thus the market is as saturated as ...

I'm not going to finish that analogy, for all our sakes.

But, at least in my city, a surprising amount of thought goes into pairing each customer with the best prostitute for his wants and needs. We're a service industry, and just because we're literally servicing our customers doesn't mean we phone it in.

Say the client gets waved over to a caller. It's not like a taxi stand, where you hop into the first available opening. The caller and the client speak for a while first. Sometimes clients have specific wants -- anything from a classy escort experience to hardcore BDSM. Then their preference is divided into age, figure, sex, and ethnicity. It's like building your own video game character, only you get to f**k it once you're done.

Ethan Miller/Getty Images News/Getty Images It'll be at least four years before you can legitimately f**k your video game character.

After the caller finds out exactly what the client wants, only then does he contact the most fitting available prostitute. For longer negotiations, the caller might even stop at a drink stand and treat the client to some booze. The customer gets their free drunk on, while the street caller talks it over with the girls until a decision is reached upon who, exactly, is the best prostitute for the job at hand.

Many massage parlors here are fronts for sex. There's no dinner, no conversation or getting to know each other a little first -- just straight to the "show." That's why the more traditional prostitutes in Saigon see massage girls as whores. (Ed. Note: If you're confused by that distinction, join the club.) Of course, I'm sure the massage girls think we're whores because we don't even throw a friendly massage in first.

Aleksan Gudenko/iStock/Getty Images "It's not all about the sex, dammit! What about the trapezius? Won't anyone think of the trapezius?"

When the caller for a moped prostitute and a pamphlet girl for a massage parlor get too close, things can explode. And not in a sexy, euphemistic way. Callers will knock the pamphlets out of the girls' hands; the girls will kick over the bikes of a rival. There's a parlor very near my room, and full-on fights over clients aren't at all uncommon. It's like a parody porno of The Warriors out there.

You don't want to know what the prostitute version of Luther sticks to her fingers.

We have each other's backs, too. If someone tries to go to a moped prostitute's apartment, they'll find that all of the neighboring apartments are also filled with prostitutes, as well as an owner who can come and pin down the abuser. Clients who get aggressive can look forward to being dogpiled by call girls, and while that does sound like a hell of a lot of fun, I can assure you it is less so in practice.

The police have no qualms with punishing tourists caught abusing women, and they can totally be reported to American authorities. One of my customers threatened me with a pocket knife when I was 16, and after I yelled out my code word, there were police on the scene in a couple of minutes (Without so much as asking if I was a prostitute, let alone arresting me).

Lisa F. Young/iStock/Getty Images The code word may or may not have been "KNIFE!"

The man was deported the next day, and last I heard, was arrested on arrival in the United States. There's this misconception that sex tourists can do whatever they want in other countries with impunity, as though that country wouldn't protect its own people over a sexually-frustrated rug salesman from Albuquerque.

NOTE: Diem retired as a prostitute shortly after our interview and opened a moped accessory shop in Ho Chi Minh City.

Evan V. Symon is the interview finder guy at Cracked and asked over 40 prostitutes before finding one willing to talk with him about being a prostitute. If you have an awesome job or experience you would like to talk with Cracked about, hit up the tipline at tips@cracked.com

For more insider perspectives, check out 6 Things You Learn When Your Penis/Vagina Doesn't Work and 5 Things You Don't Know About Strippers (Until You Are One).

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