Simply put, I like my privacy. I originally acquired a PO Box to have an address associated with my domain registrars. You have to have a physical address as a just in case. In this instance, I use a PO Box as otherwise, a billion people will know where I live, and I don’t want that.
With this in mind, I decided to publicize my PO Box in the case that someone would want to write me. As of when I check my mail, this will vary on if I’m receiving a lot of mail or not. In slow times, I may check just once a week, but in busy times – I could check twice a week. Since my PO Box is a 10 minute walk away, I can check it on a frequent basis. Also, I am guaranteed to drop off any mail at the post office when I check my mail.