Next time you impatiently yank an over-sized envelope emblazoned with the words: "You May Have Already Won 10 Million Dollars!!!" out of your junk-filled mailbox, take a moment to say: "Thanks." Without Publisher's Clearing House, the New York Botanical Garden might not havea library.The Botanical Garden's LuEsther T. Mertz Library is named for its largest benefactor, the genius behind the concept of the mass market mailing of multiple magazine subscription offers. Founded in 1953 by former librarian Mertz, her husband, and their daughter, Publisher's Clearing House became the largest and most profitable magazine circulation agency in the world. (And this...