It's cheaper to ship something UPS and have the post office deliver it "the final mile". Sometimes when a package comes via UPS Easy Post, instead of getting it when the post office says it's due, UPS will drop it off a day earlier. It's like, hey we were just in the neighborhood, so we dropped this off. And they're in my neighborhood every day. Other times I have to wait for the post office, and their Final Mile Delivery may or may not get here the day they say. UPS, FedEx, Amazon, and Home Depot do a pretty good job almost all of the time. Except they don't always leave packages at the back door like I ask them too. I had FedEx leave a box of ammo on the edge of the front porch soaking in rain, sleet, snow, and whatever else we had 12 days ago, instead of leaving it on the back porch where it would be less exposed.