Final answer:
Most network television advertising time is typically sold as spot announcements, which allows advertisers to target specific demographics by selecting appropriate times and programs.
Step-by-step explanation:
Typically, most network television advertising time is sold as spot announcements. This method of advertising allows various advertisers to purchase brief slots of commercial time during a television program's broadcast. The nature of spot announcements offers flexibility to advertisers, who can select specific times and programs to target their desired demographic, leveraging the vast amounts of television watched annually in the United States.
Over time, the television advertising landscape has evolved from single-product sponsorships to the current model where commercials are interspersed throughout programming providing opportunities for multiple advertisers. Moreover, the market demographic plays a crucial role, as sponsors can use the data gathered by network and cable television companies about their viewers to tailor their advertising strategies effectively. Cable television's rise, with its niche channels, further diversified advertising options for targeting specific audience groups.