My zip code is one of the worst in the country for USPS, neighbors go without mail for weeks or even months at a time, constantly losing packages too. Eventually I was fed up so decided to try building a relationship with the carrier, just the occasional smile and acknowledgment at first, mail service improved so much that I now throw them $20 for christmas every year. Really unfortunate that I need to bribe my mail carrier to get reasonable service, but it's absolutely worth it to me, and it definitely makes their day a bit better too which can't be bad.