Identify and describe at least four of the most impactful (in terms of numbers of viewers, revenue and margin drivers, etc.

Identify and describe at least four of the most impactful (in terms of numbers of viewers, revenue and margin drivers, etc.) forms of social media for companies and their brands that would be appropriate for global markets. Discuss the business implications and the nature of this new user-generated content along with the challenges and opportunities that various forms of social media offer firms.