Final answer:
Social media is a low-cost and efficient way for businesses to communicate CSR efforts, reaching a wide, educated, and technologically adept audience quickly.
Step-by-step explanation:
The benefit of using social media to communicate a business's CSR (Corporate Social Responsibility) efforts to the public is that it allows companies to reach broad and diverse groups directly in a low-cost, efficient way. Social media, as opposed to TV ads or government-supported direct mail campaigns, provides a platform where information can be quickly disseminated and discussion encouraged, engaging a primarily younger, more educated, and technologically savvy demographic. In the modern digital age, social media has proven to be a powerful tool for businesses to foster an image of social responsibility and gain public support for their CSR initiatives.