Connect 4 Ad - Pretty Sneaky Siss (1974)

About Connect Four, from BoardGameGeek:

Connect 4 is a well known vertical game played with "checkers" game pieces, although it is more akin to Tic-Tac-Toe or Go Moku. The board is placed in the stand to hold it vertically and the players drop game pieces into one of the seven slots, each of which holds up to six game pieces, until one player succeeds in getting four in a row, whether horizontally, vertically, or diagonally. The game is non-proprietary. More elegant, wooden versions can be found under the name The Captain's Mistress.