APC hack

This hack may only be of use in Manhattan, where the lines at the post office for human post office clerks are never short.
Much to any tech-saavy customers delight, he USPS joined the customer self-service movement a while back by installing machines/kiosks called Automated Postal Centers at many of their branches. By following directions on a touch screen, you can weigh letters and packages and purchase postage using your credit or debit card. This saves customers the trouble of waiting in line for their most common mailing needs.
The reliability of these machines, though is poor, and the glitch in the interface is that the APC often allows you to go all the way to the end of the process before informing you that, due to one error or another, you have to go to wait in line for a clerk after all.
When that happens, I've found a workaround that seems to be effective most of the time. From the opening screen, instead of hitting the "Mail a letter or package" button, press the button that says "Look Up Information." Then, press "Look Up Domestic Mailing Costs." Weigh your letter or package, type in the destination zipcode, and the machine will tell you the postage. But then it will also offer an option to purchase that postage. You can then proceed to purchase the stamp with your credit/debit card.
For some reason, that method always works, even when proceeding down that "Mail a letter or package" branch of the menu fails.