The buses I ride have for the Post Office alone four different types of advertising: (1) "Certified Mail". (2) "Stamp Containers". (3) "Wrap Right". (4) "Air Mail Service." How much does this cost over the United States and what good does it do? The Post Office is not the only one. The Navy. for example. has three different types of ads in these buses. Another one is "Launch Hope". another is "U.S. Savings Bonds". another. "World Refugee". another. "Radio Free Europe." This is just a few of them that appear in the buses alone. I am just wondering who pays for all of these things. Personally.