According to an article by Brian Solis, social media enthusiast http://www.briansolis.com/2011/02/report-in-2011-brands-make-the-pivot-to-pursue-the-social-consumer/:
A recent study showed that social media marketing accounts for 64% of the roles of employees at ad agencies. And as of 2011, marketers plan to increase their usage of social media 75%. This includes utilizing iPhone apps, video social media and blogging. In fact, 69% of marketers believe that social media is a component of an effective customer relations program.
Why the shift to marketing using social media? The answer is the rise of the social consumer. What is the social consumer? These are people who are actively engaged in using communication tools to speak their mind about products or services. This involves word of mouth and social media for criticism, praise, etc.
However, while many agencies are moving to social media, there is still a lot to learn. Especially concerning using social media strategies and tactics effectively. Social media is ever-changing, and takes a lot of focus and research to utilize it effectively.