If you are using USPS for Priority Mail, you do have the option of selecting extra services, preparing the label, and paying for the shipment on-line. For me it is so much more convenient to do this in the comfort of my own home. The post office gives a modest discount in rates if you pay on-line. Then you can either drop it off at the post office or request free carrier pick-up. Our local post office has reduced the number of clerks so much that the wait in line is now excessive.