This is what I was thinking at first. This just looks like classic chain letter.
But on rereading, it appears that the person at the top is controlling who’s sending books to who, and might even be dictating where you buy the book from, which is definitely a scam.
My guess on how this works. Upon DMing the person in control, you’re instructed to buy a book from a specific website (that they control) and have the book shipped directly from there to the “stranger.”. However, “stranger” doesn’t actually exist, no books are ever sent, and the person running this whole scam is just pocketing the money rubes spend on “books”.