Some of the largest electronic and digital media companies are part of conglomerates with diverse operations, such as Disney, with its theme parks and children's toys. Which companies you identify as the top eight in this field will depend on what criteria you use (revenue, market capitalization, etc.) and whether you count those parts of their business that do not pertain to any aspect of electronic and digital media.
Netflix, Disney, Comcast, and AT&T are certainly four of the largest. The attached analysis from the Investopedia website shows that they all have market capitalization of over $200 billion. The other four will depend very much on how you conduct your measurement. Reasonable choices might include Fox Corporation, Viacom, Discovery, and Hearst Communications.
Netflix has one of the simplest business models. It creates a great deal of original content and relies for its income on three subscription plans, with some variation (in both content and plans) according to the geographical location of the user. As a relatively new company, it has emphasized fast growth over profitability in the short term. By contrast, Disney has a more diverse model, as befits its corporate structure, creating far less original content and relying on theme parks, consumer products, and licensing for much of its income.
Netflix's mission statement is even simpler than its business model. It is "to entertain the world." This emphasizes the global nature of the company's ambitions. The statement makes sense and allows for the development of both short-term and long-term goals, but it is far too vague for most employees to apply it to their own work. Senior executives, with responsibility for commissioning, might reflect on whether the content for which they are responsible is entertaining and global in appeal. Netflix's corporate vision statement, "to continue being one of the leading firms of the internet entertainment era," is similarly vague.