Free: Contests & Raffles.
You are breaking the law about putting a flyer in their box. Be careful if you have a *censored*ty neighbor. I would call and ask. I would especially have something figued out to say to the neighbor that you suspect back there.
I hunt 99% private land so that is what I would do next time, your asking for that to happen as sad as that is in a public or "known" private area, also you wont get it back, who steals things then confesses? NO ONE... sad to hear but a very real and common thing these days......