Last month, I offered a free one-year subscription to the first person who identified how JCK's hometown—King of Prussia, Pa.—got its name. The winner is Sheldon L. Wernikoff of Wernikoff's Jewelers in Skokie, Ill., who knew the town was named for a tavern. Congratulations to Sheldon, but there's a marketing lesson to be learned by the tale—the importance of knowing who your real customers are. Locals still debate the origin of the tavern's name, but the most popular theory goes as follows: The area called King of Prussia borders Valley Forge, where George Washington and the Continental Army spent the winter of 1777-78 camped out—freezing, hungry, and barefoot—waiting for spring and a chance to rout the British from Philadelphia. The Americans were a ragtag volunteer bunch, few of whom had proper military training, so General Washington brought in mercenaries from Prussia (