I am sure every person in this world has paid it forward one way or another...I have had people send me things here and there..a picture of a family member, a book etc..(family or friends).I always am very thank-for...I never even would have thought to send postage...as I would not expect them to pay me if I sent them a book, flowers, pictures, trickets etc...also in the future...if you tell the post office its a book it a lot cheaper. I use to send books to my daughter inlaw in CA. it was like 3.00 to send...they do not weight it its one set price for books.