History of the National Football League on television
NBC was the first major television network to cover an NFL game, when on October 22, 1939, it broadcast a game between the Philadelphia Eagles and the Brooklyn Dodgers; the network was still only in its infancy, with only two affiliates, the modern day WRGB (now a CBS affiliate) in Schenectady and W2XBS in New York City. Portions of that game still survive via films, but the film is not footage from the telecast (recordings of television broadcasts did not begin until 1948). The use of a sideline camera, the sole camera used in the 1939 broadcast, would become the standard for all future NFL broadcasts until 2017; the angle is particularly suited for estimating yardage, compared to more mobile camera angles that began to appear in the 21st century.
WNBC
Although full commercial telecasting began on July 1, 1941 with the first paid advertisements on WNBT, there had been experimental, non-paid advertising on television as far back as 1930. NBC's earliest non-paid, television commercials may have been those seen during the first Major League Baseball game ever telecast, a game between the Dodgers and the Cincinnati Reds, on August 26, 1939 over W2XBS. In order to secure the rights to show the game on television, NBC allowed each of the Dodgers' regular radio sponsors at the time to have one commercial during the telecast, and these were done by Dodger announcer Red Barber. For Ivory Soap, he held up a bar of the product, for Mobil gas he put on a filling station attendant's cap while giving his spiel, and for Wheaties he poured a bowl of the product, added milk and bananas, and took a big spoonful.