Final answer:
The global media marketplace developed in the 1980s with the emergence of cable networks and specialized channels like CNN.
Step-by-step explanation:
A highly competitive global media marketplace began to develop in the 1980s. The introduction of cable networks, along with satellite broadcasts, disrupted the dominance of the major networks that operated over the air. This era saw the emergence of specialized channels, with individual programs targeting particular groups of consumers. Notably, CNN started in 1980, pioneering 24-hour news coverage, and represented a shift towards a more dynamic and competitive media environment. Furthermore, advertising revenue began to shift towards these new cable networks, signaling the rise of a new media landscape. By the 1990s, an expanded availability of satellite technology allowed consumers to bypass cable companies, amplifying the competitiveness of the media space.
The development of a global media marketplace coincides with the 'democratization' of media, including the rise of social media and the competition between traditional and electronic media forms.