For all the jibber jabber about the novelty of social media, I can't help but be cynical.
Social media has been successfully used by nonprofits for decades, mainstream for profit marketers have jumped on the bandwagon in the last decade. My experience in healthcare helped me focus on the human aspect of marketing. Who in their right mind actually enjoys having advertising thrown at them constantly? If the money grubbers hadn't been so busy milking the machine of traditional mass marketing, they wouldn't have been so late to the social media arena.
Social media is by the people for the people, and the people don't want to be continually pitched. Would you like being at a social gathering and have someone come up, get in your face with their business card as they scan the room around you? Yeah, that's definitely not exhibiting a sincere interest in you as a person.
So here's the big secret to successfully implementing social media in marketing: treat people like human beings and try to put yourself in his/her shoes.