You break the silence of the page, addressing the reader directly. "You just never know, do you?" You know the best empathy point and work toward it, the sooner the better: "They express themselves, and it always seems to end in tears." You know news value keeps readers engaged. "Maybe the best medicine is art. But no health insurance pays for that." You give the donor an important, irreplaceable role to play. You know they're all skimmers, so you respect the "F" pattern, as revealed by eye-motion studies. You know that the PS is the "real 1st paragraph of a letter." You write a tight one, restating the offer. You know that the eye skips like a butterfly, so you ask over and over, wherever that eye might alight. You know your SMIT (thank you, Jonathon Grapsas): "this wonderful thing cannot happen without your help."