Why do they do that?

You know all those jumbo shrimp you just ordered at the restaurant? Chances are they're prawns. But put the word jumbo in front of anything and customers are bound to buy it. Similarly, dry cleaning isn't really dry. Instead of using water to clean the fabric, the launderer uses an equally wet solvent called perchloroethylene. Does "dry cleaning" sound so much better than "wet cleaning"? Some launderer thought so. In this article, we'll demystify a few more intriguing business practices. We'll reveal the magic employed, the common sense practiced, the manipulation perpetrated and arm you with facts you can use to protect yourself.

Why do wafer companies put so much air in their bags?

To dupe us into thinking the foil bags are filled with chips? Actually, no. In fact, the bag don't contain oxygen. They're filled with nitrogen. Oxygen would quickly turn the chips rancid. The nitrogen preserves the freshness of the chips, prevents combustion, and creates sufficient cushioning during shipping so the chips don't get crushed. Still feel ripped off? Here's a consolation: NASA reports that bags of potato chips taken aboard super modified jets respond to the sudden change in air pressure soon after takeoff by exploding. Cool!

Why does Walt Disney World seem larger than life?

Walt Disney ingeniously used an optical illusion called forced perspective to enhance the magic of Magic Kingdom, its theme park in Florida. For example, when you enter the park, the street narrows into the distance, creating the impression that the shops stretch forever towards the enormous castle. When you walk back down Main Street, USA to leave, the reversed perspective of the widening street makes Walt Disney World train station appear closer, tricking your brain into thinking the walk in short.

Likewise, the buildings lining Main Street, USA look several stores tall because the windows, awnings, signs, and fixtures higher up are significantly smaller than those on the ground level. The same goes with the castle. It stands a mere 58 meters high and yet appears almost Empire Stateesque. That's because the windows, turrets, and fake bricks decrease in size as they near the rooflines. Disney also designed the top spire nearly half the size it should be to seem twice as tall. After all, as with shrimp, bigger is better.

Why do supermarkets have greeters?

Because shoppers like saying hello back? Well, sort of. In 1980, the manager of the Walmart store in Crowley, USA, had problems with shoplifters. So he hired a woman to stand by the front door to greet customers and ask them if they needed any help. The greeter's mere presence intimidated any potential shoplifters. After visiting the Crowley store, company founder Sam Walton quickly instituted greeters as a trademark of all Walmart stores. The benefit to customers? Less shoplifting means lower prices, which help you "Save money, Live better."

Why does Facebook encourage me to post my photos online?

Because pictures are prettier than text? While that might be true, that's not the reason. By posting your photos on Facebook, you've granted the company the license to use it. Theoretically, they can use them any way they want, whether it's for corporate promotional material or advertisements, unless you know to opt out. They also allow business that you've "liked" to use your profile photo on ads shown on your friend's pages. Most people fail to read the user agreements, which clearly says that "you grant us a non-exclusive, transferable, sub licensable, royalty free, worldwide license to use any IP [intellectual property] content that you post on or in connection with Facebook" (snore! Is it any wonder people skip this?) unless you and every one with whom you've shared your photos, deletes them. Occasionally, third party advertisers have used photos without the user's or Facebook's consent. A few years ago, a man logged on to his account and stumbled upon an ad for online dating service. Who was the star of said ad? His wife! Awkward! Turns out the service lifted her profile photo from her page.

Why do watch advertisements show the time at 10:10

Because office starts at 10 and you shouldn't be more that 10 minutes late? No, but it actually serves two ends. By keeping the hands at 10:10, they don't cover a watch's brand name or other text printed on the dial. But then, you might argue, why not use any of several other positions that don't cover the text? That's because 10:10 also frames the brand name symmetrically between the two hands. Indeed, the "opposite" position, 8:20, was used in ads long ago, but the industry realized that it resembled a face with a frowning mouth, while 10:10 looks much like a smiley. Why would you buy frown when you can just as well get a smile?