Businesses have been using gifts as bait to attract customers for at least 20 years, and a marketing professor familiar with the practice said that "there is no question that it still gets results."

One reason the technique succeeds, according to Professor M.A. Jolson of the University of Maryland's College of Business and Management at College Park, is because "reciprocity really works."

Jolson said that "there have been experiments in which there are some people sitting in a doctor's office, and one of them gets up to buy a Coke.

"He comes back with two, one for himself and one for the guy next to him; and the guy is so appreciative. And they start to talk, and the guy who bought the drinks mentions that his son is selling raffle tickets. The guy who was given the drink then feels obligated to buy some tickets, and he does buy some."

Jolson said that a higher percentage of those given drinks bought tickets than those who were not.

The professor adds, however, that companies using the gift approach sometimes antagonize more people than they attract.

"It's like throwing dirt on the wall: some sticks and some doesn't; but they are interested only in what sticks," he said. "They are living for today, and they aren't worried that what they are doing is bad for their business tomorrow."

Jolson said there are ethical and unethical ways to use gifts as bait.

"Probably you have received in the mail an offer to call an 800 number about a prize you have won, and when you do that you are told to drive to someplace in Virginia and take a tour of their development in order to receive your gift," he said. "So you drive down and you receive a TV that they paid $40 for but that may have cost you $100 at a store.

"Now, there is nothing dishonest about that. The only dishonest part is if they say you have definitely won one of these prizes when you haven't. It would be better to say you will get a TV set if you come down, rather than saying that you have won a TV set. They are embellishing the giveaway when they say that. And there is no need ever to tell an untruth."

Jolson insisted that there is "newer stuff that works better . . . but it takes some thought and maybe some money and experimentation, and a lot of people are unwilling to make the investment or be innovative in coming up with a new way of doing things."