But why?

It's actually the coffee's fault. Well, some of it at least: Consumption of caffeine makes people much easier to persuade in general. In a double-blind study, participants who took caffeine pills were far more easily convinced about the benefits of euthanasia than those who had taken placebos. Apparently, this is possible because most people don't actually listen to everything anybody else is saying. The addition of caffeine gives them that little mental boost to be more attentive and therefore more persuadable. So in a way, all those counterculture hippies were right: Starbucks is turning us all into "easily pliable sheep, man."

OH SHIT WHAT IF THEY WERE RIGHT ABOUT EVERYTHING.

Whether it's George Costanza impressing some Texas businessmen or just an American used-car salesman telling you, "This is a damn fine car! Hey, I wouldn't bullshit a bullshitter! Am I right?" cursing has its place in the business world. You're damn' right it does.

"Balls. Shit-cock. Fuck-spindle. Sign these goddamn papers. Any questions?"

But why?

You'd think that most people, if polled, would probably say that salespeople should avoid using any sort of profanity around customers. A lot of people are uncomfortable with swear words, and even those who aren't could easily find it unprofessional. It turns out, though, that's totally fucking inaccurate. By adding the phrase "dammit" to the beginning or end of a statement, researchers found that people are more inclined to agree with the speaker's opinion when the curse is used. This may be because cursing implies more passion about the subject at hand.

You really know he doesn't care where Scarlett is going to go, or what she is going to do.

But it may be precisely because you don't expect the salesperson to curse in front of you that it's so effective. So when they use profanity in a positive manner (i.e., they aren't telling you to "fuck off into a dickbasket" but are just using it to emphasize how great something is), you pay more attention to the whole argument and are more likely to think the opinion expressed was genuine. While it might seem unprofessional, a salesman using a small curse ("This is a damn good car/television/casket") is more likely to make a sale, since you probably think he's being honest about his feelings instead of just trying to trick you into the more expensive brand.

But why?

Even though the slimy fast-talking salesperson a pop culture stereotype, salespeople who speak faster are still perceived to be more intelligent and certain of what they are saying, and therefore have more trusted opinions than salespeople who speak at a "normal" conversational speed.

There is an upper limit, though; the fastest "normal" rate of speech is about 194 words a minute. If you get much higher than that you start sounding like a speed freak instead of just someone who really knows what he's talking about. So be wary if a salesperson starts upping the tempo a bit right as you try to walk away -- it doesn't mean he suddenly stopped being a douche who's trying to force something you don't need on you; it just means he may have also read this article.

Cracked.com can be used for good or evil. Please avoid the latter whenever possible.

But also watch out for...

You're walking down the street when one of those uppity, most-likely-vegan charity workers accosts you.

"Sir? Do you care about children?"

"Yes, of course I care about children."

"Well, would you sign this petition then?"

OK, you just said you like kids, so it would be kind of a dick move to back out now. You sign the petition and start to walk away, then he asks if you want a brochure. You take the brochure because, well, you did just sign the petition. You'll just throw it away later. Then he asks if you'd like to donate $10 to the charity -- it would really help the kids, you see. A whole bunch of excuses are on the tip of your tongue, but what's $10 anyway, right? You don't want to look like someone who cares about children enough to sign a piece of paper but not enough to put his money where his pen is.

In any question about children, leaving space between those last two words is VERY important.

But why?

Called the "Foot-in-the-Door" technique, this strategy is the key to upselling: It works because most people have a really hard time saying no in the first place and have an even harder time if they've already said yes to something. Salespeople exploit it by getting you to say yes to something trivial before hitting you with a much bigger request.

"Now that we've settled on a life insurance policy ... how about a threesome?"

The most famous example was a phone survey of women regarding the cleaning products they used. The women who took the survey were called again a week later with an absurdly invasive and inconvenient request: Would they allow men to come look through their kitchen cupboards for two hours to see for themselves what kind of products they use? The women who participated in the phone survey were two times as likely to let strange men poke around their houses, compared with women who were just asked the second part with no primer. You see this every day: It's why you end up with a warranty you don't want or a supersized meal you don't need. You've already said yes to buying one thing, and it's only a little more money for the upgrade, and really, when you think about it, a warranty for a taco isn't all that unreasonable: What if you drop it in the parking lot? Your hand is practically forced here!

"Only $24.99 for three years of coverage? I'd be a fool not to buy it."

You're out at a restaurant when the waiter comes over, smiles at you, tells you his name and then hunkers down to your level. He repeats your order back to you before rushing off to the kitchen, obviously because he's in such a hurry to please you, even though your meal takes forever to arrive. While you're waiting, the waiter comes over again and asks you, by name, if you would like another drink, all while lightly touching your arm. The bill comes, complete with some mints, and you open it to find he's drawn a smiley face with a little thank-you note inside.

So what's the deal? Is he going to rape you? Was he in a cult? Was it a rape-cult?! No, he just knows that after all this, you're probably going to leave him a pretty decent tip, no matter how cold and terrible your food was.

If you smile wide enough, it doesn't matter how much you spit in their coffee.

But why?

Every single thing that waiter did was a way to manipulate you into giving him more money at the end of the night. For our foreign readers who come from a "tipping is totally optional" culture, in the United States, it's kind of a big deal. The idea of leaving no tip, even after below-average service, is almost impossible to contemplate. The act of tipping your server at a restaurant is so ingrained that the government even assumes it will always happen, allowing waiters and waitresses to be paid far less than minimum wage because tip money will make up the difference, and even recently closing a loophole in order to force servers to declare tips on their taxes.

They called it "Mr. Pink's Law."

But even though tipping is expected, it doesn't mean the amount we tip can't be manipulated -- and people in the serving industry know all the tricks and use them. The difference between a 15 percent and 20 percent tip can be as simple as a smiley face drawn on your bill, a touch on your arm or a free mint with your check. Even factors that have nothing to do with table service affect the amount you tip -- like if it's sunny out, or even just the mention of sunny weather at some point. So the next time some smug, swaggering waiter comes at you talking about how much he misses spring, you just sweep his leg and run, friend -- he's trying to hypnotize you!

But why?

People are different: Right-brained vs. left-brained, creative vs. logical, touchy-feely vs. withdrawn, boisterous vs. shy. And not surprisingly, all these different types of people want different things when they're making purchases. The things that are important to you when buying a product (color, texture, sound clarity, etc.) are called your Chosen Representational System. The best salespeople recognize your CRS very quickly and adjust their selling style accordingly. If you're kind of a big guy in a Tapout shirt, they can guess that volume is probably most important to you, and they're going to crank that baby up to 11. If you're a well-dressed female, they assume you'll be more swayed by aesthetics, and they'll likely show you their low-profile, sleek systems.

Pro Tip: Faking a seizure is enough to drive away all but the most dedicated salespeople.

That's all somewhat common sense, but there are ways they tailor their pitch to you before even asking any questions: For example, changing one word when stating an opinion goes a long way toward convincing the person you are talking to that your way of thinking is correct. In general, women are swayed by "I feel" and men more by "I think." So if you're talking to a woman, then you "feel this is the best portable smoothie maker ever made." If you're talking to a male customer, you "think this smoothie maker will goddamn dominate every other one on the market."

It gets even crazier from there: Another effective tool is asking you to recall something from the past. Depending on whether you look up or down, left or right, salespeople can often infer your CRS, no matter what your subsequent answer is. That's right: Your very body language is betraying you to the salesbastards. You cannot even trust yourself against them.

The secrets don't stop here, learn more in the brand new Cracked.com book.

Be sure to learn more tricks of the trade in 5 Ways Stores Use Science to Trick You Into Buying Crap and 5 Cheap Magic Tricks Behind Every Psychic.

And stop by Linkstorm to see how the Internet tricked you into liking cats.

And don't forget to follow us on Facebook and Twitter to get sexy, sexy jokes sent straight to your news feed.

Do you have an idea in mind that would make a great article? Then sign up for our writers workshop! Do you possess expert skills in image creation and manipulation? Mediocre? Even rudimentary? Are you frightened by MS Paint and simply have a funny idea? You can create an infograpic and you could be on the front page of Cracked.com tomorrow!