Content marketing is not something mystical, like dragons or sea urchins that speak through their eyeballs. In fact, there's no question about it: An effective content marketing campaign increases traffic. An increase in traffic increases awareness around your brand. Increase awareness, and you can create dialogue, create dialogue and you can influence sales.
So, if you are looking for someone who does all this stuff and can prove that he has. Think Steve Jobs. Try and call Mark Zuckerberg. But if they aren't available, give me a shout. My beard is better than Steve's and I'm balder than Mark.