When the Chicago Tribune's Bob Greene wrote "a sip of the stuff is like biting into a hot fudge sundae," he did not realize that his words were about to unleash a torrent of Canfield's Diet Chocolate Fudge Soda on the world. Greene, whose syndicated column appears in some 200 newspapers, cooed about the two-calorie soda in "a silly throwaway column" last January. The Chicago-based A.J. Canfield company immediately was deluged with orders. "Lightning hit us, and we didn't know we were hit," says Alan Canfield, senior vice president of the firm his grandfather started 61 years ago.

In the nine days after Greene's column appeared, Canfield's sold 1.5 million cans—more than its entire 1984 production. With orders coming from as far off as Saudi Arabia and China, the frazzled company (at the time the drink was marketed only in four states) could not keep up with demand. Delivery trucks were waylaid, a bootlegged 35¢ can sold for $6 in New York, and a Sioux City, Iowa newspaper offered one as a contest prize.

Alan Canfield quickly stepped up production. To get fast delivery on necessary ingredients, he persuaded flight attendants to stow containers of ingredients in planes' bulkhead seats. To ship chocolate concentrate to bottlers, he bought first-class tickets for 10-gallon containers. Now he has franchisers in 50 states and sales have increased 5,000 percent. Not surprisingly, at least seven imitators have sprung up.

Canfield dreamed up the idea of the drink 15 years ago. A chronic dieter and chocoholic, he brought a two-pound box of fudge to the company's laboratory. "If we can duplicate this taste the world will beat a path to our door," he insisted. The entirely artificial product was perfected in 1972, but sales languished at five percent of Canfield's line of nine diet sodas.

This year the company expects to sell more than half a billion cans. "It's a pop man's dream," exults Canfield, who may be sorry that lightning never strikes the same place twice.