I work at a second hand bookshop and we buy people's unwanted books. There are often all sorts of things inside them: old bookmarks, airline tickets, photographs and newspaper or magazine pages, either reviewing the book, or on the same subject, if it's a non-fiction book. Occasionally, we find bank notes - anything from old 2 and 5 notes that have been replaced by coins to larger denominations that were put in the book and forgotten about.
Once, we had a man come in to the store to sell some expensive collector's items because he was broke and he was really sad to be parting with his books. A price was agreed upon and the man was paid. As he was leaving, my boss flipped one of the books open and money rained down all over the floor. It amounted to a few thousand and was returned to the rightful owner, who said that he had misplaced this cash some time ago. Because he had now got a similar amount to what he received for his books, my boss asked whether he still wanted to sell his books but he had made up his mind to part with them.
At least that seller got quite a bit more than he had bargained on but that story has made me mindful of not casually placing money inside books because once you start looking for it, you seldom think to check your books and I have occasionally done exactly what this particular seller had done. I also think of all the photos we find that were lost that way. While some of them have been fairly trivial in subject matter, some were clearly more important than that but had been used as bookmarks, probably because they were at someone's bedside.
We often get books when people are moving house or in a frenzy to 'tidy up my life!'. Sellers often part with more than they intended.
