Driving home from NAPEX, I stopped in Havre De Grace, Maryland for lunch and discovered a terrific bookstore, Washington Street Books & Music. They have one of the best selections of military history books I have found anywhere, not to mention games, role playing books, comics, music, dvds and an excellent selection of science fiction - all of which are right up my alley. I definitely recommend checking it out if you are in the area.
At the store I picked up a copy of a Vietnam Studies monograph I didn't have, The War in the Northern Provinces. Turning it over, I saw the book, which is around 1/2" thick, was sent through the mail as evidenced by the mailing label.
My Anthony Wawrukiewicz book on US postal rates isn't handy, so perhaps someone can explain why the monograph qualified for 3rd class mail, which is typically used for advertising or "junk" mail. Printed in the upper right corner of the label it clearly reads "Special Fourth Class Rate Books."
In addition to a useful book I got a nifty piece of postal history, not to mention a new destination to visit each year.