I think you're referring to a very vague conception of "content" and an equally vague conception of "niche market". Those buzzwords are pretty meaningless.
Basically, you're saying that "content" aka "tradable_object" (service or otherwise), must always have "market_value", if it is to be successful in a "niche market" aka "market".
He's saying that niche marketing is dependent on good content marketing, which is a fancy way of saying releasing free information to attract an audience.