My friend owns a eatery in a suburban shopping mall located at a high-class residential area.
Every weekday morning, a Japanese man in office wear will comes to his cafe and order a cup of coffee.
The coffee is made by those common coffee machine you see at most small eateries and sells for $1 a cup. So you cannot expect much in terms of its taste.
I asked my friend if he ever find out why the man does that every day and he replied no. He is not even curious. He sees this guy every day and never even talk to him once. And the guy never talk to my friend too. He does not know where does this person lives, why he comes here every day, where is he going, why he orders the same item every day.
What if my friend starts talking to him the next time he visits?
What if my friend offers him a free cup of coffee the next time he visits?
How much do you make from a cup of coffee? Probably a few cents.
How much do you gain from a cup of free coffee ? Probably cannot be measured.