I was certain Paul Gertner had put one orange sponge ball into my hand. He told me to hold it firmly. My fist hovered over a scarlet pad on the counter at the Cuckoo's Nest, the 37-year-old go-to place for magic supplies in Pittsburgh.

It was purposefully a go-to place Sunday, when 58 professional and amateur magicians converged as a "cash mob." Rick Maue, a mentalist, orchestrated the crowd of patrons to encourage support of the store and promote the idea that others can do the same for any type of ma-and-pa shop.

"Getting people together to spend a little money never hurts," he said. "With technology, [bricks-and-mortar] stores are having a hard time."

Tom Peiritsh, co-owner with his wife, Linda, said the Cuckoo's Nest, at 2304 1/2 E. Carson St., "is doing OK" and has seen a jump in Internet orders. But older magicians say there's nothing like being able to touch, fold, deal, squeeze and otherwise test the stuff of illusion before they buy.

With my fist tight around the sponge ball, I watched Mr. Gertner, a magician who travels the world professionally, hover his fist over mine until our fist shadows combined on the counter. When I opened my hand, I had both balls; his palm was empty.

If you're old enough to know there's no magic on earth, illusion may be the next best thing until it dawns on you that illusion depends entirely on your mental lapses.

"Your eyes saw A, B, C, D, E and F," Mr. Gertner said, explaining my own lapse, "but your brain saw A, B, C, D and F. The shadow had nothing to do with it."

I was somewhat gratified that the magician who fooled me is world renowned. That's not the quality of deception most fools deserve, after all. I asked him how the second ball got into my hand.

"There was a moment," he said.

"But I didn't open my hand," I protested.

He smiled, punched the air with a forefinger and said, "In your mind you didn't."

As someone who can't bear unanswerables -- and I knew I hadn't opened my hand -- I mulled it over. Those sponge balls are more compliant than the human brain. They're like dough. Maybe a magician could furtively roll one into another before jamming what looks like one ball into your fist. When you open your hand, the two balls pop apart.

Who knows, except the magician?

"There's a technical name for what I'm doing," said Mr. Gertner, slowly dealing a deck of cards as a crowd gathered around him. "It's called cheating" -- dealing cards off the bottom. "If I had done it at normal speed, you wouldn't have been able to catch it."

He fanned the deck in front of his face and asked me to pick out a card with my mind. I silently lit on the seven of spades. He cut the cards, turned one over and there it was. Before long, he was folding a $1 bill ever smaller until it turned into a $50. If it would stay a $50, magic stores wouldn't need cash mobs.

The event was such a success, Ms. Peiritsh said, "that I never moved from the front till everyone was gone. I didn't want to do it. I was afraid people would think we suggested it. We didn't even 'like' it on Facebook. But it was fun. We're tired but thrilled."

Don Moody came from Alliance, Ohio, to be part of the throng. He returns each month for meetings of the Mystic Magicians of Beaver Valley. Among several area magic clubs, his club has a "teach-and-learn" session every month.

He has spent 40 years doing stage illusions, "levitating people, cutting them into pieces" as a part-time job, he said. When he worked for National Cash Register, a magic shop in New Jersey was one of his clients.

"I was checking the cash register, and a little kid showed me how to disappear a silk handkerchief," he said. "I was hooked."

The Cuckoo's Nest sells 5,000 items, including books about Houdini, vanishing wands, multiplying golf balls, Crazy Man's handcuffs, the Hundred Dollar Bill Switch, large puppets, hand buzzers and Groucho glasses.

"The backbone of our [in-store] business comes from demonstrations," Mr. Peiritsh said. "There's usually someone here every day" to show patrons magic tricks.

Mr. Gertner made it obvious that great magicians are as intuitive as political operatives and marketing moguls in understanding how to deceive us by playing on our lapses, knowing we will miss seeing the "E" with our brains.

"In the political world, it's called spin," he said. "The magician deceives you with exaggerations, creating false patterns and taking advantage of your inclination to give everyone the benefit of the doubt."

First Published: March 5, 2013, 10:00 a.m.