Because government contractors are notoriously awful at technology being that they are selected via cronyism. This would be an expensive, proprietary label system requiring special proprietary ink and labels that would likely break after being used 50 times, and require an authorized repair contractor to fix it. A relative or friend of the executive at USPS who implemented this would receive the contract and just take the money.<p>It would also need to interface with their daily operations &quot;out for delivery&quot; db which likely is also proprietary and extremely expensive to modify, and already under an existing long term licensing contract they have no intention of changing.<p>Disclosure: this is how it worked at Postes Canada when I once worked there. All technology was long term licensed, through crony corps I had never heard of who only seemed to exist to receive money from CPC to sell extremely expensive systems that merely passed plain text to a db.