The children were much more serious about Halloween than we were.
They'd ring the bell and I'd display the goods and usually someone would ask "How many can we take?" Once I said two, one good piece and one bad, and that set them to work. Little hands hovered over the selections, and came to a group decision: Twizzlers were good and Almond Joys were bad. One defector stage-whispered to a friend as they rushed away "I took two Good ones."
Another time when asked how many I said "One point five," which puzzled them only a moment. A little pirate quickly figured it out. "Oh, that means one candy and one cards" (we also offered small decks of cards which proved unpopular). All of that group followed his example.
We had fifty to sixty kids this year. A neighborhood blog (myballard.com) provided a googlemap for households to display Halloween participation and this may have boosted activity.