I started doing ALL of my shipping thru USPS online over a year ago, unless I have to because if size and wieght limitations.
It took just a few minutes to read thru all the account details, and set up a personal home account, so now I calculate, pay and print postage on line, then check off the carrier pick-up box, and the carrier comes right to my home door the next day to get it hand to hand (or off the front porch if I can't be home). It is cheaper, easier and faster than UPS! Finally, the USPS figured out how to compete with the other carriers...