Defining Social Media Marketing

I don't like the Wikipedia definition of social media marketing, because it focuses too much on search and does not touch on corporate marketing or integration.  So let's try a new definition by thinking through the phrase "social media marketing," backwards:

• Marketing. A business function which exists to drive sales, by matching (sometimes generating) consumer need to company solutions, i.e. promotion that makes consumers aware of features and benefits, a product that fulfills a purpose, a price that the consumer is willing to pay, and a place where the solution can be obtained.
• Media. The plural of medium, a container or channel used to deliver content to individuals.
• Social. More accurately, socializing - interaction between individuals.  Call and response, idea and feedback.

Producing a definition of social media marketing:

"Interaction between individuals in [digital] delivery channels, exchanging content related to consumer needs and company solutions."

That's theory.  In practice, things start to break down and few marketers are operate in the conversational nirvana promised by social media evangelists.  Why?

• Media + Marketing. Inefficient traditional marketing, one-way delivery of sales messages.
• Social + Marketing. Unscalable marketing programs, limited by employee participation (when allowed) and uncontrollable community evangelism.
• Social + Media. Breaks when marketing content comes into play. Individuals interact by phone too, but dislike being dialed by telemarketers.

So social media marketing can be more precisely defined as:

"Interaction between a company and individual via [digital] delivery channels, intended to share commercial content that will lead to a sale and/or be passed along to others."

What am I missing here?  This sounds pretty much like traditional marketing to me.