You have three cards: A - the gimmick card, B - the advertising card, and the C - the regular card. Place card B under the flap on Card A. Place card C over the flap, but spread to look like three cards. Show cards by holding in left hand with thumb and second finger. Turn cards over, ask anyone to select middle card. After the card is withdrawn, pull card C over the flap with your thumb so that only two cards appear. Have person look at the card he selected. It is the advertising card.
