Hearing rumors that her birth control sponge has been pulled off the market, Elaine goes on a hunt for sponges based on the expectation of little future availability. Her demand has increased-she buys a case of sponges.
George gets a massage from a man and feels "it" move. Jerry asks him whether it was a "movement" of a "shift," as these are different. This scene can be compared to movements along versus shifts in demand and supply curves.