The concept of reciprocity as a mental trigger is one that caught my attention immediately. It underscores a human trait that supports the feeling that when you do something nice for a person, they feel somewhat obligated to return the favor. Of course this is not always the case, but you will find that it is true more often than not.

I remember when my wife Barbara and I were information-seeking in a flooring store in upstate New York one fall afternoon. We had no intentions of purchasing anything in that store on that particular day. We were “researching” a brand for a later purchase for when we returned to Florida. Upon entering the store we made our position…