There's even more to it. Business is good for the USPS as more people shop online. They carry a lot of packages for FedEx and UPS to places they won't go. Their pensions are overfunded by billions. This source estimates $82 billion. The article is from 2011, but the process to reclaim the money is ongoing.
http://www.pionline.com/article/20110627/PRINT/306279976/usp...