How did new, “sensational” advertisements come to exploit these markets opened by the advent of new technology in movies and radios?
During the Depression Era, people chose to escape their everyday lives by watching movies and listening to radio series.
The original question had to be edited. I think that the media of the 1930s did much to establish escapism as part of the advertising approach to selling goods and services. The printed medium as well as the medium of radio focused on how individuals wished their lives to be. The advertisements projected an image of escape and the idea that through the purchase of particular products, life could be transformed to what it might be as opposed to the often dreary condition of what was.
For advertisers in the 1930s, the emphasis on escape helped to feed the sensational nature of their work. The depiction of "rosy South Island" dreams were employed to bring out the idea of a world far removed from economic hardships. Sometimes, the sensational nature of advertisements extended to promotional offers. Advertisements with exclamations of "30,000" dollars in cash contests were specifically designed to appeal to the individual who was financially challenged by the times. The sensationalism extended to advertisement techniques such as exclusion, in which "Nobody can afford a cold this year."
In its desire to exploit the escapist element in what life was, advertisement of the 1930s embraced the sensational in an effort to convey an absolute need within the financially challenged consumer to purchase goods and services.