Social media world has been resulted as one of the best marketing platform for startups, small and mid-sized companies. They have gained number of clients as well as followers which has helped them to establish their brand as well as business in the market. Be it content distribution, campaigns or promotions, social media has always been a useful tool for SMBs, especially for those who stay conservative towards marketing expenses.
Below Infographic, by udemy, provides a very clean overview about the role of social media for SMBs and Startups. A fair comparison of various social media networks like Facebook, Twitter  and YouTube demonstrates the effectiveness of social platform.
Hope this Infographic may help you if you are a startup or want to open a company.