I recently finished reading an article entitled Why CPA's Twitter and thought most of the points were salient to all those who use social media (not only CPAs).
In summary the article rightly noted the ability to manage relationships and information as well as using social networking as a recruiting and retention tool.
As someone who works for an Interactive Media Agency, I noted that the article did not include the promotional aspect of social media and only tangentially touched on scalability.
One of the key aspects to using social media is the ability to promote yourself, your organization and otherwise influence or interact with peers and/or the general public. In addition to the tools recommended in the article, there are numerous applications one can use to promote themselves or their organization. They include Blogs, Forums, Social Bookmarking, and video/photo sharing to name a few.
The beauty of all this is that accessibility and usability are non issues in regards to social media. Anyone can access social media with a computer or a phone. Scalability can be worldwide depending on how expansive one wants to make their promotional efforts.
To have success using social media as a promotion tool it is necessary to have a strategy that helps you accomplish whatever your objective is (i.e. educate customers, generate leads, increase sales, attract candidates, build awareness etc.). In addition to many of the services we offer, Definition 6 (an Interactive Marketing Agency) has helped develop and implement social media strategies for many of its clients.