One of the reasons why social media marketing is becoming very popular compared to search engine optimization(SEO) is that social media accounts like Twitter, Instagram, Facebook of celebrities and high profile individuals are more likely to be mentioned in the social media . Any mention in the social media is a form of free advertising for the celebrity or business, so there are a large number of social media marketing agencies.
It is advisable to initially purchase a low value social media marketing package for followers for social media accounts, to check the effectiveness. Many agencies are offering low cost packages, costing between $1-$5 for a large number of followers , which are extremely affordable compared to PPC marketing using google adwords, where the cost of a single click can be $1 or more for some keywords.
It is also important to update the social media account regularly with fresh high quality content, so that it is tracked closely. The mainstream media like newspapers are closely monitoring the social media accounts of celebrities, high profile individuals and organizations.