Opening a Facebook Page, a Twitter account or a YouTube channel costs nothing. However, promotion, advertising, design and paying a team of people to maintain such social networks will incur costs. The following table shows the typical social media costs a large company incurs monthly. Costs will vary according to the size of the company, advertising used etc., the larger the business and promotion the larger the costs. This is another reason why a business should plan a strategy before the launch of the promotion.
Below is a link to a webpage, which consists of numerous infographics that summarises social media and its importance within a business.