Those are already challenges the USPS has to deal with. They have infrastructure in place to address those challenges. If they're paying those costs anyway, the

Those are already challenges the USPS has to deal with. They have infrastructure in place to address those challenges. If they're paying those costs anyway, they might as well add services that can take advantage of that investment in exchange for more revenue. There certainly would be an additional marginal cost, but it would be much, much less than an entity trying to start that from zero.