Bing! Ding! Ching! Ka-Ching! That's your music. And it is music. Because you do this little dance—more like a single dance step on repeat—all day long. You go through the same motions time and time again, and naturally you've developed a rhythm. "Find everything?" (cha-cha-cha), "Paper or plastic?" (dip-turn-spin), "Help you to your car?" (rumba-two-three).

Some of your dance partners are old hat. You've seen them for years. Every Tuesday they buy a loaf of wheat bread, a carton of milk, fruit, ten pounds of bran cereal, and toilet paper. (The amount of bran cereal purchased is in direct proportion to the amount of toilet paper.) Your dance with them is familiar. But the majority of your customers are strangers, and you mechanically "check them out." Service with a smile…and not much else.

^{Brace yourself.}

It didn't always work this way. In the 1950s, cash registers were a new-fangled thing and IBM (competing with NCR) was a really big, fat, huge—see your thesaurus for additional fitting descriptors—hairy deal. And oh, by the way, NCR (National Cash Register Company) was one of the biggest companies in the world for a short while. Be wary, Starbucks.

But in the 1950s, there were price tags and cashiers had to...find them. And when they did, they had to actually...think. That is, the wool sweater is tagged as $1.98; even at Wal-Mart that price would have made no sense. The boy tagging the sweaters clearly made a mistake—it should have been priced $19.80 and he slipped a decimal. Had you, as cashier, not caught it…well, your store would have just been ripped off. And you—along with the kid with the itchy trigger finger—would be the ones…sweating.

Also in the 1950s, things moved more slowly. People talked. Like—with their voices, not abbreviated in text format. Cashiers made it a point to be the store's "sales rep" and put a best foot forward—it was a big deal to make flirty eye contact with the customer in some form.

Oh, and there weren't credit cards either, by the way. Mind blown, right? Because everything was "cash or check," there was a certain amount of fumbling that would often take place and—always during the busiest check-out time—a little old lady would flip over her purse and 197 coins would spill out of it.

But also in those days, labor was cheaper; stores had more power, and three well-dressed boys in white would race over to clean up the coins—and actually give them back to the little old lady rather than throw them in their own pockets and run out of the store. We had this novel "respect your elders" concept that most of us stood by. The world has gotten older—not necessarily better—at least for the store check-out process.

^{Paper or plastic?}

But some things have gotten better. The biggest improvement: bar codes. We're not referring to a technology that helps you find some place that's open at midnight and is still pouring blond lager—rather, it's those parallel lines of varying thickness that you see on almost every tag attached to almost every product under the sun. In fact, the sun is one of the only things left without a bar code. We bet it would be pricey, though.

What changed? The management of light—er, waves. We learned how to measure their bounce. Notice how the bars on bar codes are of different widths? Well, the waves hit 'em, bounce back to a reader, and the varying series of widths in those bar codes basically give back to Mr. Computer a long number…which is the identifier of the product itself. And the bar codes make life oh so much better as the computer now really does more or less all of the work—making cashiers able to be, well, dumber. Phew…pressure's off.

These bar codes, combined with the cheap and easy Kim Kardashian-like ubiquity of computers, changed the role of cashier forever. Every few years, there's a cashiers' union or two that strikes; stores then put in fully automated units and the mad march toward robotizing cashiers continues.

What're the odds that this career will exist in twenty years? Eh...probably not so great. And the odds you're still seriously considering pursuing this path? Roughly the same.

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