[charshman]

>>> I feel content marketing has to evolve from mere "content" to "expertise" marketing.

I totally agree with this point.

The most trusted, shared, reputable content is either written by practitioners or, like Priceonomics says, about a company's data or industry or people.

I am a content marketer for a CRO tool and make it a point to run A/B tests on our marketing site and blog as often as possible so I know what I'm talking about. It's my editorial duty to know as much as possible about the subject I'm writing about.