Remembering the anniversary.
To take advantage of free shipping, just make an order in a particular month, containing the listed game.
Here is a list of months and game titles, in which the promotion is valid:
February - "1831: For our freedom and yours - Battle of Grochow"
February - May - "Festung Breslau 1945"
July - "Primosole Bridge 14 - 17th July 1943"
July - "Maida 1806: Stuart vs. Reynier"