A few people mail books to friends or people they know from book club lists (of some type), but most people leave their books in some public place where they are easily picked up by a stranger. Maybe in a coffee shop, or at a mall. Maybe in a doctor's office reception room, or another kind of waiting room. I haven't had any successful releases yet, but it's been less than a month. Some people try to target their book to the audience in the area. One person left several books about the movies in a movie theater, someone else left books about child-raising in a dr's office. If you read some of the release notes, and tips, you'll get it.