Honor your agreement
I made an agreement with a seller to buy his muzzleloader. He since left me a voicemail saying he had another buyer closer to his home, but wanted me to have first shot at it. I responded in 30 minutes and wouldn't you know it was sold. I really appriciate the "first chance" since we already had an arrangement. This has happened to me more times than not when dealing with classified ads. There is no consideration anymore. For those that do honor your word, thank you, you are few and far between.