I cannot resist the siren song of FREE! Great Harvest Bread Company often lures me in when I'm passing by one of its locations. I like their bread and I like to support neighborhood business. But I love getting my free hunk of bread and slathering it with butter.

In my mental calorie calculus, a free slice of bread doesn't count as a meal or a snack. From a mental accounting point of view, a free gift like a slice of bread throws me for a loop. I don't know how to evaluate the value of a slice of bread (it is probably a whopping $.15). It enables me to justify the visit.  After the bakery has lured me in the door with the gift of FREE bread, of course I'll buy a loaf of multi grain.

I see this behavior when grocery shopping too. I am a huge fan of Cooks Illustrated magazine.  I love it because the results rarely disappoint.  The recipes call for very specific ingredients and tend to be long and involved.  I can shop at the supercenter, which is less expensive but inevitably requires a second stop a a specialty grocery store for Parmesan rind or leeks or some other distinctive ingredient. Sometimes I just eliminate the trip to the supercenter and go to the more upscale grocer. I justify the more expensive prices with the knowledge that I will get a few nice snacks from the free samples on offer.

In his book "Influence:  The Psychology of Persuasion," Robert Cialdini illustrates that giving a gift changes the dynamics of the relationship. Even for a hunk of warm bread or a fancy cracker topped with aged Parmesan can impact how readily and how wide we open our wallets.  The recipient of the gift feels that she owes the retailer something in exchange. So if you are trying to sell something, sample or gift potential clients. If you are offered a gift, think about how it might influence your behavior before accepting.

I'll illustrate this concept with more examples in future posts.