There is SO much BS around Social marketing, and the "guru"s really jumped on the bandwagon didn't they...
If you use social marketing as a list-building tool and market them effectively, it can work, but I don't know anyone who is making a killing via FB. One of my businesses has around 11k solid likes, and it's another good method for staying in front of your clients and potential customers.
FB & Twitter are just the 'new' RSS feeds really from a marketing information point of view. Yes, they're interactive, but what real business has the time to sit on social media sites and chat all day - I've got money to make! The problem with the whole 'interactive' social media thing is it's a HUGE waste of time and energy 99% of the time. GREAT for social, but for business marketing, you gotta be real careful not to end up disappearing your day down the toilet!