trade show magician named Eddie Tulluck once explained crowd behavior to me — why people go where they go and stop where they stop. As with all things Eddie, his explanation was dismissive and not intended for debate. He considered crowds to be entirely predictable. “Show visitors go where they want to go,” he explained with his hallmark authority and finality. “Nothing you can do will change that.” That’s why companies hired Eddie in the first place. He understood crowds, and they didn’t. Or so he made them believe.

Eddie’s assessment may sound like hyperbole. Still, it would be a mistake to treat it lightly just because it’s a bit overblown. Every exhibitor who has ever created a program to attract attendee attention will tell you that Eddie’s observation contains a nugget of truth: Attracting a crowd is difficult.

Unfortunately, exhibitors frequently overlook the obvious and, instead, make assumptions that actually increase that difficulty. The most common — and the most dangerous — is the assumption that trade show exhibiting is easy. That simply showing up will generate business. That a hung-over staffer sitting semi-comatose in the booth will attract interested visitors. That brand presence is enough to tractor-beam buyers to the booth in captive droves. That exhibiting is like modern painting, “aw shucks, my baby brother could do that” (better, and for a lot less, no doubt).

Not surprisingly, these assumptions are wrong. Not sort of wrong, but dead wrong. How wrong is wrong? How badly can you be ignored by an audience that you’d give your first born to impress? It can be worse than you think.

A story by Gene Weingarten in the May 4 edition of the New York Times illustrates the nature of extreme rejection. The story tells how violinist Joshua Bell, one of the finest classical musicians in the world, who normally fills concert halls around the world at 200 bucks a pop, put on a pair of jeans, a long-sleeved T-shirt, and a Washington Nationals baseball cap, and played a $3.5 million Stradivarius for rush-hour commuters on the street of L’Enfant Plaza in Washington, DC. According to the article, “His performance was arranged by The Washington Post as an experiment in context, perception, and priorities — as well as an unblinking assessment of public taste: In a banal setting at an inconvenient time, would beauty transcend?”

For 43 minutes, starting at 7:51 a.m. on Friday January 12, 2007, Bell played some of the most elegant music in the world, including “Chaconne” from Johann Sebastian Bach’s Partita #2 in D Minor (considered one of the most difficult violin pieces to master), and Franz Schubert’s breathtaking “Ave Maria,” one of the most familiar religious pieces in history. Did passersby stop for his music? Did his “brand” bring foot traffic to a screeching halt, even for a moment? The short answer is “only in your dreams.”

According to Weingarten, “No crowd gathered for Bell at L’Enfant Plaza, not even for a second. In fact, for the nearly three quarters of an hour that he played, only seven people stopped what they were doing to hang around, at least briefly, to take in his performance. Twenty-seven gave money, most of them on the run, for a total of $32 and change. That meant that there were 1,070 people who simply hurried by oblivious, many of them only three feet away, few even turning to look.”

The fact is, motivating people to give you their time and attention takes work. Trade show exhibiting is neither easy nor egalitarian. It is a high risk, high reward opportunity. Each visitor has his or her own agenda, and exhibitors who assume otherwise both disrespect the visitor and short-change their companies’ investment in the opportunity, all the while setting themselves up for failure. There are many ways to attract an audience, but the most important step is to not assume it’s easy. Just ask Joshua Bell.