How not to sell your books

A book marketing newsletter I subscribe to makes this very important point:

All of marketing consists in creating relationships. Real relationships: friends, lovers, partners, warriors, fans.

Another good point is made by a subscriber describing how she sold many copies of her book at airports, restaurants etc, just by carrying copies of the book and telling people face to face about it- Instant sales.
I know I'm going to vex a few persons who might read this post, but I suspect other Caribbean (Maybe it's only in Jamaica???) writers have my experience with this relationship and face to face selling thing.It's another hazard of our small populations.

 Here's how it usually goes: You are at a function, or you meet persons you know well or not-so-well and after the greeting the conversation will go something  like this:
Friend/Foe:   I hear you have a new book out
Me:              Yeah came out earlier this year
F/F               What's the title again?                                                                                                            
Me               Bernie and the Captain's Ghost (Could be another title) It's a children's book
F/F               Where can I get a copy?
Me               It's in the book stores (Duh!)
F/F               You don't have a copy with you?
At this point you'd better say no, because if you say you do and hand it over this is what is likely to happen
F/F              Looks interesting. My son/daughter/nephew/niece/godchild/grandchild would like this.How much is it?
So you give the price gleefully smelling a sale.Then F/F says: "I don't have any cash on me, but call me later at ....... OR  I'll get it to you later" - and walks away with your book.

AND THAT IS TOO OFTEN THE END OF THAT STORY. F/F is never in when you call and if you buck up him/her later you'll get a kind of blank look. He/she can barely remember having taken your book and attitude will suggest you are planning a scam on him/.her.(You're sure I didn't pay you ?)

Then, of course, writer gets shame and drops the issue. Unfortunate!! People who would never think of going into a restaurant and not paying, have no qualms about getting your book for free. It's a mind set we seem to have- books should be borrowed or gifted, but never bought.

At a launch, people (F/Fs) will come expecting to buy a copy of your book,but after that, it's like pulling teeth with your bare hands.
Is it just me with this experience?????