I was signing books with a fellow author. She bought my book. She said that she wasn't married but she had three friends who were having problems and really needed my book. She said she was going to read it, then lend it to each one of her friends.
I let her know that in order for anyone to get any good out of the book they needed one of their very own. That way they could keep going back the the pages that pertained to them.
I reminds me of when I had the book 'Your Erroneous Zones'. That book saved my life. When I found a friend or a family member in need, I would buy them one. I was not about to give mine up. It has been used so much that it looks like it is 100 years old.